Thyroid and tiredness: when it is worth checking.

Thyroid and tiredness go together when the fatigue arrives with feeling cold, a slow gut, dry skin and two kilos gained for no clear reason. Your thyroid is one of the possible causes, not the explanation for everything. You write the signs down, and your doctor orders the tests and reads them.

It is 7 am, you have three calls and feel as if you slept in your clothes. I see it a lot in the people I work with: the tiredness has lasted for months and nobody has looked at the butterfly-shaped gland in the neck.

Thyroid and tiredness: what are the symptoms?

It is not tiredness on its own, it is the group of signs. When you also feel cold, think slowly and your gut has stopped, the thyroid belongs on the list.

In one study of people with a low thyroid hormone level, tiredness appeared in 56% of cases, feeling cold in 38%, constipation and weight gain in 36%. In another, seven signs changing made a slow thyroid far more likely.

• You feel cold. Your hands and feet are cold, and you put socks on indoors.
• Your thinking is slow. Words come out slowly, concentration drifts, your mood is low.
• Your body holds fluid. Your face is puffy on waking, your calves feel heavy, your hair is dry.

How do I know if my tiredness is my thyroid?

Through a blood test, which your doctor reads. A slow thyroid has a medical name, hypothyroidism, and the symptoms on their own are not enough.

The gland makes T4, around 80% of the total, and T3, around 20%. T3 is the active one, five times more powerful, and T4 becomes useful once the liver turns it into T3. TSH, the figure on your test result, is not from the thyroid: it is the brain's instruction.

Your TSH can look fine while the conversion of T4 into T3 goes badly. That is why free T4 and free T3 also exist, and you can ask about them.

Thyroid and weight: when the gland is slow, weight goes up because fluid stays in the tissues, visible in the calves, and because the engine runs slowly. That is why diet and the gym can seem to do nothing.

What supports your thyroid's work

Sleep, and take the pressure off. Stress that has lasted for weeks slows the conversion of T4 into T3: high cortisol gets in the way. Seven or eight hours of sleep and an evening without work count for more than any supplement.

Do not cut your carbohydrates again. This is the mistake almost everyone makes: the scales stop, so the bread, rice and potatoes go. But the conversion into T3 happens in the liver, which needs carbohydrates. Eating very little slows it down even more.

Iodine on your plate. It is the main building block of thyroid hormone: fish, seaweed, turnips, spinach and iodised salt. Too much does harm, and taking it on your own is a bad idea.

Move, but do not punish yourself. Training built around you stimulates the thyroid, while punishing sessions raise cortisol and make you lose iodine through heavy sweating. With a confirmed thyroid problem, your doctor decides.

The morning measurement. Body temperature on waking is usually between 36.1 and 36.7 degrees. Take it before getting out of bed, on seven mornings: if it stays below 36.1, take it to your doctor with your other signs.

Watch the timing of your symptoms. With a slow thyroid, tiredness is strongest in the morning and when you rest, and it eases in the evening or when you move.

Seven days of notes, and the conversation with your doctor becomes shorter and more useful.