Feeling cold isn’t just uncomfortable — when it’s persistent and out of proportion to the environment, it’s often a signal that something in your body isn’t working right. Your body is a heat-generating machine, and when you’re always cold, it usually means heat production has decreased or heat distribution has become impaired.

The most common cause of persistent cold intolerance is thyroid dysfunction — specifically, an underactive thyroid that’s not producing enough hormone to maintain normal metabolism and heat generation. But thyroid isn’t the only possibility. Anemia, poor circulation, low body weight, nutritional deficiencies, and other conditions can all make you feel cold when others are comfortable.

The good news is that most causes of cold intolerance are identifiable through blood testing and treatable once found. If you’ve accepted being “just a cold person,” it may be time to investigate whether something correctable is actually causing it.

Understanding Body Temperature Regulation

To understand why you might feel cold, it helps to understand how your body normally maintains temperature.

How the body produces heat:

You are essentially a furnace. Your body continuously generates heat through metabolic processes — the chemical reactions that convert food into energy. This heat production happens in every cell but is particularly significant in metabolically active tissues:

• Muscles: Both voluntary movement (exercise) and involuntary activity (shivering) generate substantial heat. Muscle tissue is metabolically active even at rest.
• Liver: The liver performs countless metabolic reactions that generate heat as a byproduct.
• Brain: Despite its small size, the brain’s intense metabolic activity produces significant heat.
• Brown adipose tissue: This specialized fat tissue generates heat directly through a process called non-shivering thermogenesis.

The rate of heat production is largely determined by your basal metabolic rate (BMR) — how many calories your body burns at rest. This rate is regulated primarily by thyroid hormones, which is why thyroid dysfunction has such a profound effect on temperature perception.

How the body distributes heat:

Heat generated in your core must be distributed throughout your body. This happens primarily through blood circulation:

• Warm blood from the core travels to the periphery (hands, feet, skin)
• Blood vessels dilate (vasodilation) to release heat when you’re warm
• Blood vessels constrict (vasoconstriction) to conserve heat when you’re cold

When circulation is impaired or when the body is conserving heat due to reduced production, blood flow to the extremities decreases, leaving hands and feet cold while the core stays relatively warm.

How the body regulates temperature:

The hypothalamus acts as your body’s thermostat, constantly monitoring temperature and adjusting heat production and distribution:

• When too warm: Blood vessels dilate, sweating begins, metabolic rate may decrease
• When too cold: Blood vessels constrict (especially in extremities), shivering begins, metabolic rate increases

This system normally keeps core body temperature remarkably stable around 98.6°F (37°C). When you persistently feel cold despite normal ambient temperatures, something in this system — heat production, distribution, or regulation — isn’t working properly.

When Feeling Cold Is a Symptom

Everyone feels cold sometimes — that’s normal. But persistent cold intolerance that represents a change from your baseline or that’s disproportionate to the environment suggests an underlying cause.

Normal cold sensitivity:

• Feeling cold in objectively cold environments
• Cold hands and feet that warm up quickly with movement or warmth
• Feeling colder after sitting still for long periods
• Individual variation in temperature preference (some people run warmer or cooler)
• Feeling cold when tired, hungry, or sleep-deprived
• Age-related changes in temperature sensitivity

Cold intolerance that suggests an underlying cause:

• Feeling cold when others are comfortable — you’re the only one reaching for a sweater
• A change from your previous baseline — you used to tolerate cold fine, now you can’t
• Cold intolerance that’s progressive — getting worse over time
• Hands and feet that are persistently icy, even in warm environments
• Needing significantly more layers or higher thermostat settings than before
• Cold intolerance accompanied by other symptoms (fatigue, weight changes, dry skin)
• Difficulty warming up even with blankets, hot drinks, or warm baths
• Low measured body temperature (below 97.8°F consistently)

Accompanying symptoms that provide clues:

Cold intolerance rarely occurs in isolation. The symptoms that accompany it often point toward specific causes:

• Cold + fatigue + weight gain + constipation + dry skin: Strongly suggests hypothyroidism
• Cold + fatigue + shortness of breath + pale skin: Suggests anemia
• Cold + numbness/tingling + color changes in fingers: Suggests circulation problems (Raynaud’s)
• Cold + weight loss + anxiety + rapid heartbeat: May suggest hyperthyroidism with peripheral vasoconstriction (less common presentation)
• Cold + dizziness + low blood pressure: May suggest adrenal insufficiency
• Cold + excessive thirst + frequent urination: May suggest diabetes affecting circulation

Hypothyroidism: The Most Common Cause

If there’s one condition most strongly associated with feeling cold all the time, it’s hypothyroidism. Cold intolerance is so characteristic of an underactive thyroid that it’s considered a cardinal symptom — one of the first clues that prompts healthcare providers to check thyroid function. Approximately 5% of adults have hypothyroidism, with many more cases going undiagnosed because symptoms develop gradually.

How thyroid affects body temperature:

Thyroid hormones (T3 and T4) are the primary regulators of metabolic rate throughout your body. They control how fast cells burn fuel and produce energy — and heat is an inevitable byproduct of this energy production. Every cell in your body is essentially a tiny furnace, and thyroid hormones control how hot that furnace burns. When thyroid hormone levels are low:

• Reduced basal metabolic rate: Cells throughout the body slow down, burning less fuel and producing less heat. This can reduce heat production by 15-40% in significant hypothyroidism — that’s a dramatic decrease in your body’s internal heating system.
• Decreased thermogenesis: The body’s ability to generate heat in response to cold is impaired. Normally, when you get cold, your metabolism increases to produce more heat. This adaptive response doesn’t happen as effectively in hypothyroidism.
• Reduced core temperature: Many people with hypothyroidism have measured body temperatures consistently below 98.6°F — sometimes 97°F or even lower. They’re not just feeling cold; they actually are colder.
• Impaired peripheral circulation: The body conserves its reduced heat production by preferentially keeping the core warm, reducing blood flow to extremities. This makes hands and feet particularly cold.
• Reduced brown fat activity: Brown adipose tissue is specialized fat that generates heat through non-shivering thermogenesis. Thyroid hormones stimulate brown fat activity, so low thyroid function means this heat source is also diminished.
• Muscle-related heat loss: Thyroid hormones affect muscle function, and the muscle weakness of hypothyroidism may reduce heat production from muscle activity.

The result is that people with hypothyroidism feel cold because they literally are colder — they’re producing less heat at the cellular level, and what heat they do produce is being conserved centrally rather than distributed throughout the body.

Characteristics of thyroid-related cold intolerance:

• Generalized feeling of being cold — not just hands and feet but overall coldness, as if you can’t get warm from the inside
• Cold intolerance that developed gradually over months or years — you may not have noticed until you realized you’ve been adding layers for a long time
• Needing the thermostat higher than others in the household — conflicts over temperature settings are common
• Wearing more layers than seems reasonable for the weather or environment
• Cold hands and feet that don’t warm up easily even with gloves, socks, or heating pads
• Feeling cold even in objectively warm environments — summer doesn’t help
• Low measured body temperature when you check it — consistently below 98°F
• Dreading air conditioning and seeking out warm environments
• Difficulty tolerating swimming or cold water that others find refreshing

Other symptoms typically present with hypothyroidism:

• Fatigue and low energy — often profound, not relieved by sleep
• Unexplained weight gain or difficulty losing weight despite efforts
• Constipation — gut motility slows along with everything else
• Dry skin and dry, brittle hair
• Hair loss, including the characteristic thinning of the outer third of eyebrows
• Brain fog, difficulty concentrating, and memory problems
• Depression or low mood — often misdiagnosed as primary depression
• Muscle weakness, aches, stiffness, and cramps
• Slower heart rate (bradycardia)
• Puffy face, especially around the eyes
• Hoarse or deeper voice
• Heavy or irregular menstrual periods in women
• Elevated cholesterol — thyroid hormones affect lipid metabolism
• Slowed reflexes

The more of these symptoms you have alongside cold intolerance, the more likely hypothyroidism is the cause. Cold intolerance plus fatigue plus unexplained weight gain is a particularly telling combination that strongly suggests thyroid dysfunction warrants investigation.

Hashimoto’s thyroiditis:

Hashimoto’s thyroiditis — an autoimmune condition where the immune system progressively attacks and destroys the thyroid gland — is the most common cause of hypothyroidism in developed countries. It affects women 5-10 times more often than men and often runs in families.

Hashimoto’s typically develops slowly over years, with symptoms gradually worsening as thyroid function progressively declines. This insidious onset means cold intolerance often creeps up on you — you may not notice until you realize you’ve been adding layers, turning up the heat, and avoiding cold situations for months or years. People often attribute their increasing cold sensitivity to aging, stress, or other factors before realizing it’s thyroid-related.

Identifying Hashimoto’s specifically (rather than just hypothyroidism) matters because:

• It confirms the cause is autoimmune, not something else
• Antibodies can be detected before TSH becomes abnormal, allowing earlier awareness
• It’s associated with other autoimmune conditions that may also need monitoring
• Some people consider dietary and lifestyle modifications to support autoimmune health

Subclinical hypothyroidism:

Some people have “subclinical” hypothyroidism — TSH is elevated above the reference range but thyroid hormones (T4, T3) are still in the normal range. The body is working harder to maintain normal thyroid hormone levels, but for now it’s succeeding.

Whether subclinical hypothyroidism causes symptoms like cold intolerance is debated in medicine. Research is mixed, but many people with subclinical hypothyroidism report feeling cold, fatigued, and mentally foggy — and some report improvement when treated. If your TSH is at the higher end of “normal” or slightly elevated and you’re experiencing symptoms, it’s worth discussing with your healthcare provider whether your TSH might not be optimal for you specifically.

What to test:

TSH (Thyroid-Stimulating Hormone) is the primary screening test. Elevated TSH indicates the pituitary is working harder to stimulate an underperforming thyroid — like pressing the gas pedal harder because the engine isn’t responding normally.

Free T4 (Free Thyroxine) measures circulating thyroid hormone that’s available to tissues. Low free T4 with elevated TSH confirms hypothyroidism. This combination tells you the thyroid isn’t producing enough hormone despite being stimulated to do so.

Free T3 (Free Triiodothyronine) measures the active thyroid hormone — T3 is what actually affects cells and metabolism. Some people have adequate T4 but impaired conversion to T3, which can cause symptoms including cold intolerance even when TSH and T4 look acceptable. Checking T3 provides a more complete picture.

TPO antibodies (Thyroid Peroxidase Antibodies) identify Hashimoto’s thyroiditis. Positive antibodies indicate autoimmune thyroid disease, even if TSH is currently normal. Having antibodies predicts future thyroid decline and explains why the thyroid is struggling.

Thyroglobulin antibodies are another marker for autoimmune thyroid disease that can be positive in Hashimoto’s, sometimes even when TPO antibodies are negative.

Anemia: When Oxygen Delivery Is Impaired

Anemia — reduced red blood cells or hemoglobin — is another common cause of feeling cold. It’s often underappreciated as a cause of cold intolerance because people focus on the more obvious symptoms like fatigue. But when you’re anemic, your blood carries less oxygen to tissues, which fundamentally affects energy production and heat generation.

How anemia causes cold intolerance:

• Reduced oxygen delivery: Hemoglobin is the oxygen-carrying protein in red blood cells. With less hemoglobin or fewer red blood cells, less oxygen reaches tissues throughout your body. Since oxygen is essential for aerobic metabolism — the primary way cells produce energy — this directly impairs heat production. Cells can’t burn fuel efficiently without adequate oxygen, so they generate less heat.
• Compensatory vasoconstriction: When oxygen delivery is reduced, the body prioritizes vital organs (heart, brain) over less critical tissues. Blood flow to the skin and extremities decreases as vessels constrict to redirect blood centrally. This leaves hands and feet cold while trying to preserve core function.
• Reduced metabolic rate: Without adequate oxygen, cells can’t maintain normal metabolic function. The overall metabolic rate decreases as the body adapts to limited oxygen availability, reducing total heat production.
• Cardiovascular compensation: The heart works harder to circulate the reduced oxygen-carrying capacity — heart rate increases and the heart pumps more forcefully. But despite this extra work, peripheral tissues still receive less oxygen than they need for optimal heat generation.
• Muscle effects: Muscles are major heat producers. Anemia impairs muscle oxygenation, reducing both strength and heat generation from muscle activity.

Characteristics of anemia-related cold intolerance:

• Cold hands and feet particularly prominent — though overall coldness can occur
• Feeling cold accompanied by significant fatigue and weakness
• Shortness of breath, especially with exertion — even climbing stairs may be difficult
• Pale skin — check inside lower eyelids (should be red, not pale pink), nail beds, and palms
• Dizziness or lightheadedness, especially when standing quickly
• Rapid heartbeat (tachycardia), especially with activity — the heart compensates for reduced oxygen-carrying capacity
• Headaches
• Difficulty concentrating
• Cold intolerance that worsens with physical activity (when oxygen demands increase)

Types of anemia that cause cold intolerance:

Iron deficiency anemia: The most common type of anemia worldwide, affecting an estimated 2 billion people globally. Iron is essential for hemoglobin production — without adequate iron, the body can’t make enough functional hemoglobin. Common causes include heavy menstrual periods, pregnancy, GI bleeding (ulcers, polyps, cancer), poor iron absorption (celiac disease, gastric bypass), and inadequate dietary intake (especially in vegetarians and vegans).

Vitamin B12 deficiency anemia: B12 is required for proper red blood cell formation. Without it, the body produces fewer, larger, dysfunctional red blood cells that can’t carry oxygen efficiently. B12 deficiency is common in vegans (B12 is found almost exclusively in animal products), older adults (reduced absorption), and people with absorption problems or taking certain medications.

Folate deficiency anemia: Folate (vitamin B9) is also needed for red blood cell production. Deficiency causes a similar pattern to B12 deficiency.

Anemia of chronic disease: Chronic inflammation from any cause (autoimmune disease, chronic infection, cancer) can impair red blood cell production and iron utilization, causing anemia even when iron intake is adequate.

Other types: Hemolytic anemias (red cells destroyed prematurely), aplastic anemia (bone marrow failure), and other conditions can also cause anemia and cold intolerance.

What to test:

Hemoglobin and hematocrit diagnose anemia — reduced values confirm you have fewer red blood cells or less hemoglobin than normal. These are the primary screening tests for anemia.

Ferritin reflects iron stores and is the most sensitive marker for iron deficiency. Low ferritin indicates iron deficiency, which is the most common cause of anemia worldwide.

Serum iron, TIBC (Total Iron Binding Capacity), and transferrin saturation provide additional information about iron status and help distinguish iron deficiency from other causes of low ferritin.

MCV (Mean Corpuscular Volume) measures the average size of red blood cells and helps identify the type of anemia. Low MCV (microcytic anemia) suggests iron deficiency. High MCV (macrocytic anemia) suggests B12 or folate deficiency.

Vitamin B12 and folate should be checked if MCV is elevated or if risk factors for deficiency are present.

Reticulocyte count can help determine if the bone marrow is responding appropriately to anemia.

Iron Deficiency Without Anemia

Here’s something important: you can be iron deficient and feel cold without meeting criteria for anemia. Iron deficiency progresses through stages, and cold intolerance can occur before hemoglobin drops to “anemic” levels.

How iron deficiency without anemia causes cold intolerance:

• Impaired thyroid function: Iron is required for the enzyme that converts T4 to active T3. Iron deficiency can impair this conversion, causing symptoms of hypothyroidism even when the thyroid itself is functioning normally.
• Reduced myoglobin: Iron is essential for myoglobin, the oxygen-storing protein in muscles. Reduced myoglobin impairs muscle function and heat generation.
• Mitochondrial effects: Iron is essential for the electron transport chain in mitochondria. Even without anemia, low iron can impair cellular energy production.

What to test:

Ferritin is the key test. You can have low ferritin (depleted iron stores) while hemoglobin is still normal. This stage of iron deficiency can still cause symptoms including cold intolerance.

Poor Circulation

If your cold intolerance is primarily in your hands and feet while your core feels relatively warm, circulation problems may be the cause. When blood doesn’t flow adequately to the extremities, those areas become cold regardless of how much heat the body is producing centrally.

Raynaud’s phenomenon:

Raynaud’s involves exaggerated vasoconstriction — blood vessel narrowing — in response to cold or emotional stress. Normally, blood vessels in the fingers and toes constrict somewhat when exposed to cold to help conserve core body heat. In Raynaud’s, this response is dramatically exaggerated.

During a Raynaud’s episode:

1. Blood flow to fingers and/or toes is dramatically reduced due to intense arterial spasm
2. Affected digits turn white (pallor) as blood drains away
3. They may then turn blue (cyanosis) as remaining blood loses oxygen
4. As circulation returns, they turn red (hyperemia) and may throb or tingle

Episodes can be triggered by mild cold that wouldn’t affect most people — reaching into the refrigerator, holding a cold drink, walking through an air-conditioned store. Emotional stress can also trigger episodes in some people.

Raynaud’s comes in two forms:

• Primary Raynaud’s (Raynaud’s disease): Occurs without underlying disease, more common, usually less severe. Most people with Raynaud’s have this form. It typically begins in the teens or twenties and may improve with age.
• Secondary Raynaud’s (Raynaud’s phenomenon): Associated with underlying conditions — connective tissue diseases (scleroderma, lupus, rheumatoid arthritis), certain medications, occupational exposure to vibrating tools, or other conditions. Often more severe with more significant tissue damage risk.

If you have symptoms of Raynaud’s, especially if severe or starting after age 30, evaluation for underlying conditions is important.

Peripheral artery disease (PAD):

Peripheral artery disease involves narrowing of arteries supplying the extremities, usually due to atherosclerosis (buildup of fatty deposits in artery walls). Reduced blood flow causes cold feet and legs, along with other symptoms.

PAD is more common in people with:

• Diabetes
• High blood pressure
• High cholesterol
• History of smoking
• Older age
• Family history of cardiovascular disease

Symptoms of PAD include:

• Cold feet and lower legs
• Leg pain or cramping when walking (claudication) that improves with rest
• Numbness or weakness in legs
• Slow-healing wounds on feet or legs
• Hair loss on legs and feet
• Shiny skin on legs
• Weak or absent pulse in feet
• Erectile dysfunction in men (due to reduced blood flow)

PAD is a marker of systemic atherosclerosis, meaning if you have it in your legs, you likely have it elsewhere (including coronary arteries). This makes it important to identify and address.

Diabetes-related circulation problems:

Diabetes damages blood vessels over time through several mechanisms, impairing circulation particularly to the extremities. Both the large arteries (causing PAD as described above) and small blood vessels are affected. Cold feet can be an early sign of diabetic vascular disease.

Additionally, diabetes can cause peripheral neuropathy — nerve damage that can impair the perception of temperature and pain in the feet. This is dangerous because you might not notice injuries or temperature extremes.

Venous insufficiency:

When veins don’t efficiently return blood from the legs to the heart, circulation is impaired. While this more commonly causes warmth, swelling, and heaviness in the legs, it can contribute to overall poor circulation and temperature dysregulation in the lower extremities.

Signs of circulation-related cold intolerance:

• Cold primarily affects hands and feet, not the whole body — your core temperature feels normal
• Core body temperature when measured is normal (around 98.6°F)
• Color changes in fingers or toes — turning white, blue, or red
• Numbness, tingling, or pins-and-needles in extremities
• Slow wound healing on feet or legs
• Hair loss on legs, feet, or toes
• Shiny, thin skin on legs
• Weak or absent pulse in feet
• Pain in legs with walking that improves with rest
• Symptoms that are triggered by specific circumstances (cold exposure, stress)

What to test:

Fasting glucose and HbA1c screen for diabetes, which affects circulation through multiple mechanisms.

Lipid panel including LDL cholesterol, HDL cholesterol, and triglycerides — high LDL and triglycerides contribute to arterial disease.

hs-CRP — this inflammation marker can indicate vascular disease risk and underlying inflammatory conditions.

If secondary Raynaud’s is suspected (older onset, severe symptoms, asymmetric involvement), autoimmune markers like ANA (antinuclear antibodies) may be indicated to check for underlying connective tissue disease.

For suspected PAD, ankle-brachial index (ABI) testing — comparing blood pressure in the ankle to blood pressure in the arm — is a non-invasive screening test (not a blood test, but important for evaluation).

Nutritional Deficiencies

Several nutritional deficiencies beyond iron can contribute to cold intolerance.

Vitamin B12:

B12 deficiency can cause anemia (which causes cold intolerance as discussed above) and also affects nerve function. Peripheral neuropathy from B12 deficiency can impair temperature sensation, and the metabolic effects of B12 deficiency may reduce heat production.

Vitamin D:

Some research links vitamin D deficiency to cold intolerance, though the mechanism isn’t fully understood. Vitamin D affects muscle function, and deficiency causes muscle weakness that may reduce heat generation from muscle activity.

Iodine:

Iodine is essential for thyroid hormone production. Severe iodine deficiency causes hypothyroidism and associated cold intolerance. While frank iodine deficiency is rare in developed countries (due to iodized salt), it can occur in people who avoid iodized salt and don’t eat seafood or dairy.

What to test:

Vitamin B12 — check especially if vegan, over 50, or taking medications that affect absorption.

Vitamin D — deficiency is common and worth checking regardless of symptoms.

Iodine status is harder to test reliably. Thyroid function tests (TSH, Free T4) would detect hypothyroidism from iodine deficiency.

Low Body Weight and Body Composition

Body composition significantly affects cold tolerance. People with less body fat and muscle mass tend to feel colder.

How body composition affects temperature:

• Fat insulation: Subcutaneous fat provides insulation, reducing heat loss. People with very low body fat lose heat more quickly.
• Muscle heat production: Muscle is metabolically active and generates heat. Less muscle means less baseline heat production.
• Metabolic adaptation: The body may reduce metabolic rate to conserve energy when energy intake is low, reducing heat production.

Conditions associated with low weight and cold intolerance:

• Eating disorders (anorexia nervosa) — cold intolerance is a hallmark symptom
• Unintentional weight loss from any cause
• Very low body fat percentage (athletes, bodybuilders during cutting phases)
• Malabsorption conditions causing weight loss
• Chronic illness causing cachexia

If cold intolerance coincides with significant weight loss, the underlying cause of weight loss needs investigation.

Hormonal Causes Beyond Thyroid

Adrenal insufficiency:

The adrenal glands produce cortisol, which plays a role in metabolism and temperature regulation. Adrenal insufficiency (Addison’s disease) can cause cold intolerance along with fatigue, weakness, weight loss, low blood pressure, and hyperpigmentation of the skin.

Hypopituitarism:

The pituitary gland controls multiple hormone systems. Pituitary insufficiency can cause deficiencies in thyroid hormone, cortisol, and other hormones, leading to cold intolerance among other symptoms.

Sex hormone changes:

Some women notice increased cold sensitivity during certain phases of the menstrual cycle or during menopause. Estrogen affects blood vessel dilation and may influence temperature perception.

What to test:

Morning cortisol screens for adrenal insufficiency. Very low morning cortisol warrants further investigation.

If pituitary problems are suspected, a broader hormone panel may be needed.

Other Conditions That Cause Cold Intolerance

Hypothermia risk factors:

Certain conditions increase susceptibility to feeling cold and developing actual hypothermia:

• Advanced age: Older adults have reduced ability to sense cold (so they may not realize they’re cold until it’s severe), reduced metabolic rate generating less heat, less muscle mass, and sometimes reduced mobility that prevents them from taking action to warm up. Hypothermia in the elderly can occur even indoors with seemingly adequate heating.
• Diabetes: Autonomic neuropathy (nerve damage affecting the autonomic nervous system) can impair temperature regulation. Diabetic neuropathy may also prevent people from sensing cold in their feet.
• Parkinson’s disease: Affects the hypothalamus and autonomic nervous system, impairing the body’s ability to regulate temperature. People with Parkinson’s often report feeling cold.
• Severe infections (sepsis): While fever is typical with infection, severe sepsis can actually cause low body temperature (hypothermia) — this is an ominous sign requiring emergency treatment.
• Alcohol use: Alcohol causes vasodilation (blood vessel widening), which increases heat loss from the body’s surface. It also impairs judgment about cold and the ability to take protective action. People can feel warm while actually losing body heat rapidly.
• Hypothalamic disorders: The hypothalamus is the body’s thermostat. Damage or dysfunction (from tumors, trauma, stroke, or other causes) directly impairs temperature regulation.

Chronic fatigue syndrome / ME:

Temperature dysregulation, including cold intolerance, is commonly reported in chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS). Many people with ME/CFS report feeling cold frequently, having difficulty maintaining body temperature, and experiencing unusual temperature fluctuations. The exact mechanism isn’t fully understood but may relate to autonomic nervous system dysfunction.

Fibromyalgia:

Many people with fibromyalgia report cold sensitivity as one of their symptoms. This may be related to autonomic dysfunction that’s common in fibromyalgia, sensitized nervous system responses, or other factors. Cold can also worsen fibromyalgia pain for some people.

Postural orthostatic tachycardia syndrome (POTS):

POTS and other forms of dysautonomia (autonomic nervous system dysfunction) often involve temperature dysregulation. People with POTS may experience cold extremities due to abnormal blood vessel responses, along with their other symptoms of heart rate and blood pressure abnormalities.

Medications:

Some medications can cause or contribute to cold intolerance:

• Beta-blockers: Reduce heart rate and can impair peripheral circulation, causing cold hands and feet. Examples include metoprolol, atenolol, and propranolol.
• Some blood pressure medications: Various antihypertensives can affect circulation or metabolism in ways that increase cold sensitivity.
• Medications that cause anemia: Some medications cause anemia as a side effect, which then causes cold intolerance.
• Medications affecting thyroid function: Lithium, amiodarone, and some other medications can affect thyroid function, potentially causing hypothyroidism and cold intolerance.

If cold intolerance started after beginning a new medication, review this possibility with your healthcare provider.

Sedentary lifestyle:

Physical inactivity contributes to cold intolerance in several ways:

• Less muscle mass (muscles generate heat)
• Less immediate heat generation from movement
• Potentially reduced metabolic rate over time
• Reduced cardiovascular fitness affecting circulation

Regular physical activity improves cold tolerance by building muscle, boosting metabolism, and improving circulation. Even someone with underlying hypothyroidism or mild anemia will likely feel warmer if they’re more physically active.

The Testing Strategy for Cold Intolerance

When cold intolerance is persistent and unexplained, comprehensive testing can identify the cause.

Core tests for cold intolerance:

Thyroid panel (essential):

• TSH
• Free T4
• Free T3
• TPO antibodies

Blood count and iron status:

• Complete blood count (hemoglobin, hematocrit, MCV)
• Ferritin
• Iron

Metabolic markers:

• Fasting glucose
• HbA1c

Vitamins:

• Vitamin B12
• Vitamin D

Additional tests based on symptoms:

• If fatigue, weakness, low blood pressure: cortisol
• If Raynaud’s features or autoimmune symptoms: ANA
• If circulation concerns: lipid panel, additional vascular evaluation

What to Do With the Results

If hypothyroidism is found:

Treatment with thyroid hormone replacement (levothyroxine) typically resolves cold intolerance as thyroid levels normalize. Many people notice improvement in cold tolerance within weeks of starting treatment, with full resolution taking a few months as metabolism stabilizes.

If anemia is found:

Treatment depends on the type of anemia. Iron deficiency anemia is treated with iron supplementation. B12 deficiency anemia is treated with B12 supplementation (oral or injections depending on the cause). As hemoglobin normalizes, cold intolerance typically improves.

If iron deficiency without anemia is found:

Iron supplementation can replenish stores and may improve cold intolerance, especially if iron deficiency was affecting thyroid hormone conversion or muscle function.

If circulation problems are identified:

Treatment depends on the cause. Raynaud’s may be managed with lifestyle measures (keeping warm, avoiding triggers) or medications. Peripheral artery disease requires cardiovascular risk management. Diabetes-related circulation problems require good glucose control.

If vitamin deficiencies are found:

Supplementation to normalize levels may improve symptoms, though the evidence is strongest for B12 and iron.

When Tests Are Normal

Sometimes comprehensive testing returns normal results, yet cold intolerance persists. This is actually useful information — it rules out the most common medical causes. Consider these possibilities:

• Normal variation: Some people genuinely run cooler than others without any medical cause. Body temperature varies among individuals, and some people have naturally lower metabolic rates. If you’ve always been cold and testing is normal, this may simply be your baseline — not a disease, just your physiology.
• Low body weight or body fat: Thin individuals naturally feel colder due to less insulation and sometimes less muscle mass generating heat. This isn’t necessarily pathological, but it does explain the symptom. Gaining muscle mass (which generates heat) may help more than gaining fat.
• Sedentary lifestyle: Physical activity generates heat and builds heat-producing muscle. If you’re sedentary, increasing activity may improve cold tolerance significantly — sometimes more than any other intervention.
• Subclinical or early thyroid dysfunction: TSH may be in the “normal” reference range but not optimal for you specifically. If TSH is at the higher end of normal (say, 3.5-4.5) with symptoms suggesting hypothyroidism, it’s worth discussing with your provider whether this might not be optimal for you. Some people feel better with TSH in the lower end of normal.
• Environmental factors: Sometimes the environment is genuinely cold — poor insulation, drafty home, sedentary work in heavily air-conditioned offices. Others may have simply adapted to the cold environment while you haven’t.
• Autonomic dysfunction: Some conditions affect the nervous system’s control of blood vessel dilation and temperature regulation in ways not detected by standard blood tests. This can be difficult to diagnose but may be suggested by other symptoms of autonomic dysfunction.
• Raynaud’s without obvious color changes: Mild Raynaud’s may cause cold hands and feet without the dramatic color changes that make it easy to recognize.
• Psychological factors: While cold intolerance is usually physical, anxiety can cause peripheral vasoconstriction (cold hands and feet), and heightened attention to body sensations can amplify awareness of cold.
• Clothing and behavioral factors: Some people simply don’t dress warmly enough, underestimating their need for layers. Adjusting clothing habits and keeping extremities covered can make a significant difference.

If tests are normal but cold intolerance is significantly affecting your quality of life, it’s reasonable to try practical strategies (dressing warmly, increasing physical activity, ensuring adequate nutrition) while remaining open to re-evaluation if symptoms change or new symptoms develop.

Practical Strategies While Investigating

While working to identify the cause of cold intolerance, these practical strategies can help you feel more comfortable:

• Layer strategically: Multiple thin layers trap heat better than one thick layer because air between layers acts as insulation. Start with a moisture-wicking base layer, add insulating middle layers, and finish with a windproof outer layer when outdoors.
• Keep extremities warm: A significant amount of heat can be lost through hands, feet, and head. Insulated socks, gloves or mittens, and hats prevent significant heat loss. Mittens are warmer than gloves because fingers share warmth.
• Protect your core: When your core gets cold, your body will reduce blood flow to extremities to preserve core temperature. Keeping your torso warm helps keep your hands and feet warmer.
• Stay active: Physical movement generates heat immediately, and regular exercise builds muscle that produces heat at rest. Even brief walking breaks during sedentary work can help.
• Eat regular meals: Digestion generates heat through the thermic effect of food. Eating regularly helps maintain body temperature. Protein has the highest thermic effect, generating the most heat during digestion.
• Stay hydrated: Dehydration impairs circulation, which affects heat distribution. Warm beverages provide both hydration and direct warming.
• Limit alcohol: While alcohol makes you feel warm initially by dilating blood vessels and increasing blood flow to the skin, it actually increases heat loss and lowers core body temperature.
• Consider warm-water immersion: Warm baths or showers can raise core temperature temporarily and provide comfort.
• Use heating aids wisely: Heated blankets, heating pads, and hand warmers can provide targeted warmth. Electric blankets can pre-warm your bed.
• Adjust your environment: If possible, raise the thermostat, use space heaters safely, and minimize exposure to drafts and air conditioning.
• Optimize sleep warmth: Use adequate blankets, wear socks to bed if feet are cold, and ensure your bedroom isn’t too cold.

These strategies address the symptom while you work with your healthcare provider to identify and treat any underlying cause.

The Bottom Line

Always feeling cold when others are comfortable isn’t just a personality quirk or something you have to live with — it’s often a signal that something in your body isn’t working optimally. Your body is designed to generate and maintain heat, and when this system fails, there’s usually an identifiable reason.

The most common cause is hypothyroidism, where reduced thyroid hormone production literally slows down your body’s heat-generating metabolism at the cellular level. This is such a classic presentation that cold intolerance should always prompt consideration of thyroid function. But anemia, iron deficiency (even without anemia), circulation problems, and other conditions can also make you perpetually cold.

The good news is that most causes of cold intolerance are detectable through straightforward blood tests and treatable once identified:

• Hypothyroidism responds well to thyroid hormone replacement — many people notice improved cold tolerance within weeks of starting treatment
• Anemia improves with treatment of the underlying cause — iron supplementation for iron deficiency, B12 for B12 deficiency
• Iron deficiency without anemia often responds to iron supplementation
• Circulation problems can be managed with lifestyle changes, medications, or treatment of underlying conditions

If you’ve resigned yourself to being “just a cold person” — if you’ve accepted that you’ll always need extra layers, always be the one turning up the thermostat, always be dreading air conditioning — it may be worth questioning that assumption. A comprehensive blood panel checking thyroid function, blood count, iron status, and relevant vitamins can identify whether a treatable condition is making you cold.

You don’t have to be cold forever. Finding and treating the underlying cause can help you finally feel warm again — and that’s worth investigating.

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Key Takeaways

• Persistent cold intolerance often signals an underlying condition — it’s not just something you have to accept
• Hypothyroidism is the most common cause — an underactive thyroid reduces metabolic rate and heat production throughout the body
• Anemia impairs oxygen delivery — which affects energy production and heat generation in every cell
• Iron deficiency can cause cold intolerance even without anemia — ferritin testing can identify this
• Circulation problems cause cold extremities — while core temperature remains normal
• B12 and vitamin D deficiencies may contribute — these are common and worth checking
• Low body weight reduces insulation and heat production — muscle mass and body fat both affect cold tolerance
• Key tests include thyroid panel, CBC, ferritin, and B12 — these cover the most common causes
• Treatment of the underlying cause typically resolves cold intolerance — you don’t have to be cold forever
• If tests are normal, you may naturally run cool — but ruling out treatable causes is worthwhile