Always cold: why you feel chilly when others do not

How the body keeps you warm

Body temperature is controlled by the hypothalamus in the brain, which balances heat production from metabolism and muscle with heat loss through the skin. Thyroid hormone sets the pace of metabolism, red blood cells carry the oxygen needed to produce energy, and body fat provides insulation. When any of these are low, you may feel cold more easily.

Hands and feet are usually the first to feel cold, because the body narrows blood vessels in the extremities to protect core temperature. A whole-body chill and cold hands and feet alone can point to different causes.

Common causes

MedlinePlus lists several causes of cold intolerance. In midlife, the most common include:

• Underactive thyroid (hypothyroidism), often with fatigue, weight gain, dry skin, constipation and thinning hair
• Iron-deficiency anemia, often from heavy periods, with fatigue, pale skin and cold hands and feet
• Low vitamin B12, more common with age, metformin use and long-term acid reducers
• Very low body fat, under-eating or rapid weight loss, including during weight-loss treatment
• Raynaud's phenomenon, in which fingers or toes turn white or blue in cold or stress
• Narrowed leg arteries from atherosclerosis, causing a cold foot or calf pain on walking
• Chronic illness and general poor health
• Some medications, such as beta-blockers, which can make hands and feet feel colder

Is it hormonal?

Thyroid hormone is the main hormonal driver of cold intolerance, and hypothyroidism is more common in women and in people over 60, according to the NIDDK. Perimenopause can cause temperature swings in both directions; some women feel chills after a hot flash. Estrogen and testosterone are not typical causes of persistent coldness on their own, so it makes sense to check thyroid and blood counts before looking elsewhere.

When to see a doctor urgently

Feeling cold is rarely an emergency, but these situations need prompt help:

• Call 911 for cold with confusion, extreme drowsiness, slurred speech or a very slow pulse, which can signal dangerously low body temperature or severe hypothyroidism
• Seek prompt care for fingers or toes that turn white or blue with pain, numbness or sores that do not heal
• Seek same-day care for a single cold, pale or bluish foot, or calf pain at rest
• See a clinician soon for cold intolerance with unexplained weight gain, hoarseness, puffiness of the face or legs, or significant fatigue
• Get help if you are losing weight unintentionally or struggling to eat enough

What testing can help

MedlinePlus lists a complete blood count, a comprehensive metabolic panel, TSH and thyroid hormone levels as tests that may be done for cold intolerance. Ferritin and other iron studies, vitamin B12 and folate, and glucose or A1c are commonly added.

Circulation problems are diagnosed by examination and, if needed, simple tests that compare blood pressure in the arms and ankles. Raynaud's phenomenon is usually diagnosed from the history and appearance of the fingers, sometimes with blood tests to look for an associated autoimmune condition.

Treatment options in general terms

Treatment depends on the cause. Hypothyroidism is treated with thyroid hormone replacement, usually levothyroxine, with blood tests to adjust the dose. Iron deficiency is treated with iron supplements or intravenous iron, along with finding the source of iron loss. B12 deficiency is treated with oral or injected B12. If under-eating is the issue, increasing energy and protein intake, sometimes with a dietitian's help, is the fix.

For Raynaud's, keeping the whole body warm, wearing gloves and warm socks, avoiding smoking and managing stress help; some people need medication. Narrowed arteries require cardiovascular risk management and sometimes procedures.

Simple ways to stay warmer

While you are getting checked, dress in layers, keep your hands, feet and head covered, and avoid long periods of sitting still. Warm drinks and a warm bath before bed can help you fall asleep comfortably. Regular movement and strength training generate heat and build muscle, which helps over time. Eating regular meals with enough protein matters more than any single warming food.

How HealifyMD can help

A HealifyMD clinician can order labs for thyroid, iron, B12 and blood sugar, review your medications, and help you act on the results. If you are on a weight-loss program, we can check whether rapid weight loss or low intake is contributing. The Comprehensive Lab Panel is $199 (one-time), confirmed at the eligibility review. Circulation problems and Raynaud's are referred for in-person examination.