Hypothyroidism (underactive thyroid): the symptoms in the order they come, who is affected, the tests (TSH, free T4, antibodies), treatment with levothyroxine, what you can do yourself, and the link to tiredness, feeling cold, weight gain and hair loss

The thyroid sits like a butterfly in front of the windpipe and makes the hormones thyroxine (T4) and triiodothyronine (T3), which set the speed of every cell in the body: how much heat you produce, how fast the heart beats, how quickly the gut works, how the skin and hair renew, how the brain thinks. The pituitary in the brain measures the level and sends TSH (thyroid-stimulating hormone) to drive the gland; when the gland makes too little, TSH rises. Hypothyroidism is when the gland can no longer keep up, and everything in the body runs slow. It is the most common hormone disease after diabetes, affects five to ten times more women than men, and becomes more common with age. The most common cause is Hashimoto's disease, where the immune system slowly breaks down the gland, and the symptoms come over years, which is why so many are diagnosed late. The treatment is simple once the diagnosis is made: the missing hormone in tablet form, levothyroxine, and most people feel like themselves again within a few months. This guide covers the symptoms, who is affected, the tests and what the values mean, the treatment and how to take it right, self-care, when it is something else, and the link to tiredness, feeling cold and hair loss.

Symptoms of hypothyroidism, in the order they usually come

In the elderly the symptoms are often just tiredness, low mood, constipation and worse memory, and are confused with ageing or dementia. In younger women they are confused with stress, burnout, iron deficiency and perimenopause, which moreover are often present at the same time.

Who is affected, and why

• Hashimoto's thyroiditis (autoimmune) is the cause in eight out of ten cases: the immune system forms antibodies (TPO antibodies) against the gland, which is slowly destroyed over years. Hereditary, and more common with other autoimmune disease (type 1 diabetes, coeliac disease, B12 deficiency from pernicious anaemia, vitiligo, rheumatism).
• Women: five to ten times more common than in men; one in ten women over 60 has hypothyroidism, and many more have a mild form.
• After childbirth: one in twenty women gets a transient thyroid inflammation in the first year, often with an overactive phase followed by an underactive one; one in four of them gets lasting hypothyroidism. Tiredness and low mood after childbirth should always be tested.
• After treatment of an overactive thyroid (radioiodine, surgery) and after radiation to the neck.
• Medicines: lithium, amiodarone, interferon, certain cancer medicines (immunotherapy), large iodine doses.
• Iodine deficiency is unusual in countries with iodised salt, but occurs with a strict vegan diet without an iodine source and with non-iodised flake salt and sea salt.
• Congenital hypothyroidism is detected through newborn screening.
• Age: TSH rises naturally somewhat with age, and a mild elevation in healthy people over 70 often doesn't need treatment.

The tests: TSH, free T4 and antibodies, and what the values mean

TSH is the screening test: the pituitary's signal to the gland. High TSH means the pituitary is trying to drive a gland that isn't keeping up. The reference range is roughly 0.4–4.0 mIU/l (varies somewhat between labs). Free T4 is the hormone the gland actually makes. Interpretation:

TPO antibodies show whether the cause is Hashimoto's and predict that a subclinical form will progress; they only need to be taken once. T3 is rarely taken when investigating an underactive thyroid. Take the test in the morning, not during or just after an infection, and say if you take biotin (hair supplements), which interferes with the analysis and can give falsely normal values. Ask to see the numbers: a TSH of 3.8 "within reference" in someone with all the symptoms, antibodies and a wish to conceive is handled differently from a symptom-free 75-year-old. In pregnancy TSH should be under 2.5 in the first trimester, and the need for levothyroxine rises by 25–50 percent from week four to six, so women with hypothyroidism who become pregnant should raise the dose immediately and be tested early.

Treatment with levothyroxine, and how to take it right

1. Levothyroxine is synthetic T4, identical to the body's own, and replaces what the gland doesn't make. Starting dose often 25–50 micrograms, in young and healthy people sometimes the full dose straight away (1.6 micrograms per kilo), in the elderly and heart patients low and slow. The dose is adjusted by TSH every six to eight weeks until the value is in the lower half of the reference range (often 0.5–2.5) and you feel well.
2. Take the tablet the same way every day: on an empty stomach in the morning with a glass of water, 30–60 minutes before breakfast and coffee, or at bedtime at least three hours after the last meal. Absorption is halved by food and above all by iron, calcium, magnesium, acid blockers, soy and coffee; keep four hours between it and iron and calcium tablets.
3. Time: energy and warmth come back after two to four weeks, gut and skin in one to two months, the weight (fluid) in a few months, hair and nails in three to six months, mood and thinking over three to six months. If you still feel unwell at the right TSH after six months: check ferritin, B12, vitamin D, sleep and whether you take the tablet correctly, before the dose is raised; overdosing gives palpitations, anxiety, sleep problems, weight loss and in the long run osteoporosis and atrial fibrillation.
4. Lifelong treatment with Hashimoto's; yearly TSH check once the dose is set, more often in pregnancy, with weight change, a new medicine or new symptoms. Switching brand can change absorption slightly, test after a switch.
5. Combination treatment with T3 (liothyronine) is tried in a minority who don't feel well on T4 alone despite normal TSH, via an endocrinologist. Desiccated pig thyroid (NDT) gives uneven levels and is not recommended.

What you can do yourself

• Regularity with the tablet is the most important thing; a forgotten dose is taken the same day when you remember, two missed days are not compensated with a double dose but taken as usual.
• Iodine in moderation: iodised salt or fish, shellfish, milk and eggs. No iodine supplements, kelp or spirulina (too much iodine worsens Hashimoto's).
• Selenium (100–200 micrograms, or two Brazil nuts a day) lowers TPO antibodies somewhat in studies but has not been shown to improve symptoms; harmless in moderate dose.
• Check iron, B12 and vitamin D: the deficiencies are more common with autoimmune thyroid disease, give the same tiredness, and iron deficiency moreover impairs the action of thyroid hormone. Coeliac disease is more common with Hashimoto's and should be tested with gut symptoms or poor absorption of levothyroxine.
• Movement and strength training once the tiredness has eased: the muscles are the body's radiators and furnace, and the weight that has gone up only comes down with hormone plus movement and food, not with hormone alone. Start with walks; see how many steps a day.
• Sluggish gut: fibre, fluids, movement, clockwise abdominal massage; see sluggish bowels and constipation.
• Dry skin and dry hair: oil and emollients, milder shampoo, see dry scalp.
• Sleep and stress: cortisol from chronic stress inhibits the conversion of T4 to the active T3; sleep, stress management and recovery are not a luxury but part of the treatment.
• Gluten-free, "thyroid diets" and detox have no support unless you have coeliac disease. Cabbage, broccoli and soy in normal amounts are harmless.

When it isn't the thyroid

Tiredness, feeling cold, weight gain and low mood are unspecific, and in most people tested TSH is normal. Then the explanation usually lies in iron deficiency (ferritin, not just haemoglobin), B12 deficiency, vitamin D deficiency, sleep deprivation and sleep apnoea, burnout, depression, perimenopause, diabetes, or several of them at once. Ask for the whole panel at one visit instead of one test at a time.

Cupping, movement and heat while the treatment is adjusted

In the first months, before the levothyroxine has reached full effect, you can make the evenings warmer and the muscles softer without interfering with the treatment. Cupping of calves, thighs and back increases local blood flow several times over and warms for hours, which helps with cold legs and feet; cupping of neck, shoulders and lower back releases the stiffness and muscle aches that hypothyroidism causes; and clockwise abdominal massage with a light cup helps the sluggish gut along. Draw the dynamic cup with oil slowly towards the heart on the legs, across the shoulders, and clockwise on the stomach, ten to fifteen minutes, three to four evenings a week, followed by warm socks and a glass of water. Cupping doesn't affect the thyroid and doesn't replace the hormone, and with untreated hypothyroidism with a very slow pulse, swelling and breathlessness, take it easy until the treatment is under way. Don't cup directly over the thyroid on the front of the neck (no effect, and the skin there is thin), not with a goitre that presses, and read when to avoid cupping. Swollen legs from fluid respond well to light lymphatic massage and cupping towards the groin.

Read more

Tiredness, always cold, iron deficiency, B12 deficiency, hair loss, sluggish bowels, palpitations, and menopause.

Frequently asked questions

What are the first symptoms of hypothyroidism?

Tiredness that sleep doesn't help, feeling cold easily, and an increased need for sleep usually come first, followed by weight gain of a few kilos, constipation, dry skin, dry and thinner hair, low mood, slow thinking, muscle aches and stiffness, a slow pulse and heavier periods. The symptoms creep in over months to years and are confused with stress, ageing, iron deficiency and menopause, which are often present at the same time.

Which thyroid tests should you have, and what do the values mean?

TSH is the screening test (roughly 0.4–4.0 is normal): high TSH with low free T4 is hypothyroidism, slightly raised TSH (4–10) with normal T4 is subclinical hypothyroidism, retested after two to three months. TPO antibodies show whether the cause is autoimmune (Hashimoto's). Take the test in the morning, not during an infection, and skip biotin for a few days before. Take ferritin, B12 and vitamin D at the same time, which give the same symptoms.

How do you take levothyroxine correctly?

The same time every day, on an empty stomach with water 30–60 minutes before breakfast and coffee, or at bedtime three hours after the last meal. Keep four hours between it and iron, calcium, magnesium and acid blockers, which halve absorption. Test TSH every six to eight weeks until the dose is set, then yearly, and raise the dose immediately in pregnancy. A forgotten dose is taken the same day, not doubled the next.

How long does it take to feel better on levothyroxine?

Energy and warmth return after two to four weeks, gut and skin in one to two months, the fluid weight in a few months, hair and nails in three to six months, and mood and mental sharpness gradually over three to six months. If you still feel unwell at the right TSH after six months: check ferritin, B12, vitamin D, sleep and how you take the tablet before the dose is raised; too high a dose gives palpitations, anxiety and in the long run osteoporosis.

Does cupping help with hypothyroidism?

Not with the disease itself; the hormone is the treatment. But while the dose is being set, cupping of calves, thighs and back makes the evenings warmer and the muscles softer, cupping of neck and shoulders releases the stiffness, and light abdominal massage helps the sluggish gut. Ten to fifteen minutes a few evenings a week, not over the thyroid on the neck, and gently with untreated hypothyroidism and a very slow pulse.

Written by Curam. Last updated 17 October 2026. This is general self-care information and does not replace medical care. For sudden, severe or unusual symptoms, contact your doctor. Talk to your doctor before cupping if you are pregnant, take blood thinners or have a condition affecting skin, blood vessels or blood.