You are the one still wearing a jumper when everyone else is comfortable. Your hands and feet feel like ice from October onwards, and on top of that you are tired. In a British November it is easy to put all of that down to the weather, and often that is exactly what it is.
But feeling the cold more than the people around you, especially with low energy, is also a classic sign of an underactive thyroid. This guide explains that connection, gives fair space to the other common causes (iron deficiency, low body weight, circulation problems such as Raynaud’s, and some medicines), and covers which blood tests are worth doing and when to see your GP instead.
Is it the weather, or is it you?
Everyone feels colder in winter. A few signs suggest there may be more to it:
- You feel cold when others in the same room are comfortable.
- It is new, or noticeably worse than in previous winters.
- It comes with other changes, such as tiredness, weight gain, dry skin, constipation, hair shedding or low mood.
- Your fingers or toes change colour in the cold, turning white or blue.
- It carries on into spring and summer, when the weather is no longer a good explanation.
If several of these apply, it is worth looking into.
How your thyroid controls your temperature
Your thyroid gland makes two hormones, thyroxine (T4) and triiodothyronine (T3). Together they set the pace of your metabolism, and metabolism is also how your body generates heat. When the thyroid is underactive (hypothyroidism), everything slows down, including heat production, so you feel the cold more.
The pituitary gland in your brain notices the shortfall and releases more thyroid-stimulating hormone (TSH) to push the thyroid harder. That is why a raised TSH is usually the first sign of an underactive thyroid on a blood test.
Being sensitive to the cold rarely appears on its own. The NHS lists it alongside:
- Extreme tiredness
- Weight gain
- Constipation
- Difficulty concentrating or thinking clearly
- Low mood or depression
- Dry skin, dry hair or hair loss
- A croaky (hoarse) voice
- Irregular or heavy periods, if you have them
The NHS says the main cause in the UK is Hashimoto’s disease, an autoimmune condition that is most common in women and usually starts between the ages of 30 and 50, though anyone can get an underactive thyroid. Symptoms usually develop slowly and get worse over time, which is why it is so easy to blame on another cold winter. Unlike the weather, it does not ease when the days get longer.
An overactive thyroid tends to cause the opposite, with sensitivity to heat, nervousness, anxiety and a fast or irregular heartbeat among the NHS-listed symptoms. Our guide to thyroid blood tests for an underactive or overactive thyroid covers both patterns in more detail, and our thyroid symptoms page summarises when to test.
Other reasons you might always feel cold
The thyroid is one important cause, but it is not the only one, and for many people it is not the answer. These are the others worth knowing about.
Iron deficiency and anaemia
Your red blood cells use iron to carry oxygen around the body. The NHS lists tiredness and lack of energy, shortness of breath, noticeable heartbeats, paler skin and headaches as the common symptoms of iron deficiency anaemia. Some NHS trust patient information also lists unusually cold hands and feet among the signs of anaemia. Iron stores (ferritin) can run low before anaemia shows up on a basic full blood count, so a “normal” blood count does not rule it out. British Society of Gastroenterology guidance says a ferritin below 30 µg/L is generally indicative of low iron stores, and that ferritin can look normal in iron deficiency when there is inflammation.
Heavy periods, pregnancy, blood donation, a diet low in iron and conditions that affect absorption, including coeliac disease, all raise the risk. See our guide to what low ferritin feels like and our iron deficiency page. Iron deficiency without an obvious cause, particularly in men and in women after the menopause, should always be investigated by your GP, because it can be a sign of blood loss from the gut.
Vitamin B12 deficiency
Low vitamin B12 can cause anaemia and tiredness, and the NHS lists pins and needles among its symptoms, which some people describe as odd sensations in the hands and feet. NICE guideline NG239 treats a total B12 below 180 ng/L as confirming deficiency, with 180 to 350 ng/L indeterminate and needing interpretation alongside your symptoms. Deficiency is more likely on a vegan diet without supplements or fortified foods, in older adults, and in people taking metformin or proton pump inhibitors such as omeprazole long term.
Low body weight or eating too little
Being underweight or eating very little can leave you feeling the cold more. If you have lost weight without trying, or you are worried about how little you are eating, see your GP.
Circulation and Raynaud’s
Raynaud’s affects the blood supply to the fingers and toes. The NHS describes the skin turning white, then blue, then red as blood flow returns, often with pain, numbness or pins and needles, lasting from a few minutes to a few hours. It is sometimes caused by another health condition, such as lupus or rheumatoid arthritis, or by certain medicines, and a GP may arrange tests if they think it could be a sign of something more serious. The NHS advises seeing a GP if your symptoms are very bad or getting worse, affect only one side of your body, start for the first time after the age of 30, or come with joint pain, skin rashes or muscle weakness.
Peripheral arterial disease, where narrowed leg arteries reduce blood flow, typically causes an ache in the legs when walking that eases after a few minutes of rest, according to the NHS. Skin on the toes or lower limbs becoming cold and numb is a warning sign of severe disease. Smoking is the most significant risk factor, and diabetes, high blood pressure and high cholesterol also raise the risk. It needs a GP assessment. HbA1c, the standard blood sugar test, is included in our General Wellness panel; our HbA1c guide explains the number.
Medicines
Some medicines cause cold hands and feet. The NHS lists cold feet and hands among the common side effects of beta blockers, which are prescribed for conditions such as high blood pressure and heart problems. Do not stop a prescribed medicine on your own; talk to your GP or pharmacist.
What a blood test can check
A blood test can rule the common measurable causes in or out in one appointment:
| Possible cause | What is measured |
|---|---|
| Underactive thyroid | TSH, Free T4 and Free T3 |
| Autoimmune thyroid disease (Hashimoto’s) | TPO antibodies and thyroglobulin antibodies |
| Iron deficiency or anaemia | Ferritin, serum iron, TIBC and transferrin saturation, full blood count |
| B12 deficiency | Vitamin B12 |
| Raised blood sugar | HbA1c |
Here is where those markers sit in our panels:
- General Wellness (£279) is the natural starting point for feeling cold and tired, because it checks thyroid function and iron together. It includes a full blood count, iron studies including ferritin, vitamin D, B12 and folate, thyroid function, CRP and ESR, zinc, liver and kidney function, a lipid profile (cholesterol) and HbA1c, so it also covers the blood sugar check above.
- Hair Loss Essentials (£249) includes thyroid function alongside ferritin and iron studies, vitamin D, B12, folate, a full blood count, zinc and CRP. It suits you if you are also noticing more hair shedding.
- The Hormone Specialist (£299) includes thyroid function alongside DHT and the wider androgen panel, total testosterone, SHBG, LH, FSH, prolactin, oestradiol, zinc and CRP. It suits cold intolerance with low libido or mood change, but it does not include iron studies or a full blood count.
In all three panels, thyroid function means TSH, Free T3 and Free T4.
Thyroid antibodies are not included in any of our fixed panels. TPO and thyroglobulin antibodies can be added through a custom panel, with the price confirmed in writing before you book. If your question is only about your thyroid, see our thyroid blood test page.
For the most accurate result, book a morning appointment, as TSH follows a daily rhythm. Take levothyroxine after your blood draw, not before. Stop biotin (common in hair, skin and nail supplements) for 3 days beforehand, as it can interfere with thyroid results, and hold B12, folate or multivitamin supplements as your panel instructions say, as recent supplementation can mask a real deficiency.
Understanding your results
TSH and Free T4 are read together. Typical adult ranges are around 0.27 to 4.2 mIU/L for TSH and 12 to 22 pmol/L for Free T4, although each laboratory quotes its own. NICE guideline NG145 defines subclinical hypothyroidism as a TSH above the reference range with free T4 within it. Broadly:
- High TSH with low Free T4 points to an underactive thyroid.
- High TSH with normal Free T4 is subclinical hypothyroidism, where the thyroid is struggling but still coping. Whether it needs treatment depends on your symptoms, antibodies and history.
- Normal TSH and Free T4 make an underactive thyroid an unlikely explanation for feeling cold, which points attention back towards iron, B12, weight and circulation.
Our guide to reading TSH and Free T4 together explains each pattern. Every result is reviewed by a GMC-registered doctor against your symptoms. Results are released as each marker is reviewed, with the expected timeframe confirmed at booking.
If an underactive thyroid is confirmed, treatment is levothyroxine, prescribed and monitored by your GP or an endocrinologist. We do not prescribe it, but you will receive a written report to share with your GP.
When to see your GP, or get urgent help
See your GP if you:
- notice a lump or swelling in your neck
- have lost weight without trying
- have Raynaud’s symptoms that are very bad, one-sided, new after 30, or come with joint pain, rashes or muscle weakness
- get leg pain on walking that eases when you stop
- are found to be iron deficient without an obvious reason
Call 999 or go to A&E if a hand, foot or leg suddenly becomes cold, pale or blue, painful or numb; if you have chest pain or severe breathlessness; or if someone who is very cold becomes confused, shivers, has pale, cold skin or slurred speech, or breathes slowly, which can be signs of hypothermia.
Common questions
Can an underactive thyroid make only my hands and feet cold? An underactive thyroid tends to make you feel generally cold, not just at the fingertips. Fingers or toes that turn white or blue in the cold point more towards Raynaud’s, which is a circulation problem rather than a thyroid one. Both are common, and it is possible to have both.
My TSH was normal. Could it still be my thyroid? A normal TSH makes an underactive thyroid unlikely, and Free T4 adds confirmation. NICE guideline NG145 suggests considering thyroid antibodies (TPO) in adults whose TSH is above the reference range, so they are not usually the answer to feeling cold when thyroid function is normal. That is the point to look more closely at iron, B12, weight and circulation.
Should I just take an iron supplement? Not without a test. Iron tablets are only appropriate once a deficiency and its cause have been confirmed, which is a job for your GP.
Is this the same as being tired all the time in winter? They often overlap. See our guides to feeling tired all the time in winter, being always tired no matter how much you sleep and checking vitamin D in winter.
Related reading
- Positive TPO Antibodies With a Normal TSH: what positive thyroid antibodies mean when TSH is normal.
- Biotin and Blood Tests: Can It Skew Results?: how biotin can skew results and how long to stop it.
- NHS or Private Blood Test? How to Choose: when an NHS test is the right first step and when a private test makes sense.
Sources
- NHS: Underactive thyroid (hypothyroidism); Overactive thyroid (hyperthyroidism); Iron deficiency anaemia; Vitamin B12 or folate deficiency anaemia; Raynaud’s; Peripheral arterial disease (PAD); Beta blockers; Hypothermia. nhs.uk
- NICE Guideline NG145: Thyroid disease: assessment and management. nice.org.uk
- NICE Guideline NG239: Vitamin B12 deficiency in over 16s: diagnosis and management. nice.org.uk
- British Society of Gastroenterology: Guidelines for the management of iron deficiency anaemia in adults (Snook et al, Gut 2021). bsg.org.uk
This article is for general information only and does not constitute clinical advice. If you have concerns about your symptoms, book an appointment or speak to your GP.