Cold Intolerance: Why Am I Always Cold?

Why some people feel colder than others

Body heat comes mainly from metabolism, especially in muscle and organs. Fat insulates, and blood vessels in the skin narrow to keep heat in the core. Anything that slows metabolism, reduces muscle or fat, lowers red blood cells, or narrows blood vessels can make you feel colder.

Some groups naturally feel cold more:

• Women, who on average have less muscle and narrower skin blood flow in the hands and feet
• Older adults, with slower metabolism and reduced sensation of temperature
• Lean people with little body fat
• People who are sedentary for long periods

Common causes of cold intolerance

Hypothyroidism

An underactive thyroid slows metabolism. Cold intolerance comes with tiredness, weight gain, constipation, dry skin, thinning hair, slowed thinking, heavy periods and a puffy face. It is especially common in women over 50 and after pregnancy. A simple TSH blood test diagnoses it. See hypothyroidism.

Anemia

Fewer red blood cells carry less oxygen, and the body diverts blood away from the skin. Iron-deficiency anemia is most common, from heavy periods, pregnancy, low iron intake or gut blood loss. Look for pale skin, tiredness, breathlessness, headaches and brittle nails. Vitamin B12 deficiency can cause anemia plus tingling and numbness.

Low body weight and under-eating

Very low body fat and not eating enough energy slow metabolism to conserve fuel. Cold intolerance is a classic feature of anorexia nervosa, along with fine body hair, low heart rate and missed periods. Strict diets and intense exercise without enough food do the same thing.

Raynaud's phenomenon

Blood vessels in the fingers and toes overreact to cold or stress. Digits turn white, then blue, then red as blood returns, with numbness and throbbing. Primary Raynaud's is common and harmless. Secondary Raynaud's, linked to scleroderma, lupus or other conditions, starts later in life and can cause ulcers. See Raynaud's phenomenon.

Poor sleep and fatigue

Sleep deprivation reduces heat production and makes you feel colder.

Medicines

Beta-blockers (which reduce blood flow to the hands and feet), some migraine medicines, decongestants and stimulants that narrow blood vessels can make the hands and feet cold.

Less common causes

• Peripheral artery disease: narrowed leg arteries cause a cold foot, leg pain on walking and slow-healing sores. More common in smokers and people with diabetes.
• Diabetes: nerve and blood vessel damage cause cold, numb feet.
• Hypopituitarism: a pituitary problem causing low thyroid and adrenal hormones.
• Adrenal insufficiency: fatigue, low blood pressure, weight loss and salt craving.
• Chronic kidney disease and liver disease.
• Fibromyalgia, in which people often report temperature sensitivity.

Clues to the cause

How doctors find the cause

A doctor will ask how long you have felt cold, whether it is your whole body or mainly hands and feet, and about weight changes, energy, periods, diet, medicines and color changes in the fingers. They will check weight, heart rate, blood pressure, skin, pulses in the feet and the thyroid.

Common blood tests:

• thyroid-stimulating hormone (TSH) and free T4
• complete blood count and ferritin (iron stores)
• vitamin B12 and folate
• glucose or HbA1c
• kidney and liver function
• morning cortisol if adrenal problems are possible

Treatment and what helps

Treating the cause

• Hypothyroidism: daily thyroid hormone (levothyroxine); cold intolerance improves over weeks.
• Anemia: iron or B12 replacement and treatment of the cause of blood loss.
• Under-eating: restoring enough nutrition; eating disorder treatment if relevant.
• Raynaud's: keeping warm, stopping smoking, and medicines such as nifedipine for frequent attacks.
• Medicines: your doctor may switch a drug that is causing cold extremities.

Staying warm

• Dress in layers, with a hat, gloves and warm socks. Heat escapes fastest from uncovered skin.
• Keep moving: short walks or stretches every 30 to 60 minutes when sitting.
• Eat regular meals; digestion produces heat.
• Avoid smoking, which narrows blood vessels.
• Warm your bed before sleeping, and keep indoor temperatures comfortable, particularly for older adults.

Frequently asked questions

Why am I always cold?

Common reasons include an underactive thyroid, anemia, low body weight or eating too little, poor sleep, Raynaud's phenomenon and certain medicines. Some people, especially lean women and older adults, naturally feel colder. If it is new or comes with fatigue or weight change, get a blood test.

Is cold intolerance a sign of hypothyroidism?

Yes, it is one of the classic symptoms. An underactive thyroid slows metabolism, so the body makes less heat. It usually comes with tiredness, weight gain, constipation, dry skin and thinning hair. A TSH blood test confirms or rules it out.

Can anemia make you feel cold?

Yes. With fewer red blood cells, less oxygen reaches tissues and the body reduces blood flow to the skin. People with iron-deficiency anemia often have cold hands and feet, pale skin, fatigue and breathlessness. Treating the anemia usually improves the cold sensitivity.

Why are my hands and feet always cold?

Cold hands and feet are often due to narrowing of small blood vessels to save heat, which is normal in cool weather and more common in women. Raynaud's phenomenon, anemia, hypothyroidism, smoking, beta-blockers, diabetes and peripheral artery disease are medical causes worth checking.

What vitamin deficiency makes you feel cold?

Iron deficiency is the most common, because it causes anemia. Vitamin B12 and folate deficiencies can also cause anemia and cold intolerance. A blood test can check all three. Do not start iron supplements without testing, as too much iron is harmful.