Hyperthyroidism

What it feels like

Weight loss despite a good appetite, a racing or irregular heartbeat, tremor, heat intolerance and sweating, anxiety and irritability, poor sleep, loose stools, muscle weakness in the thighs, and lighter or absent periods. In older people it can be far quieter — sometimes atrial fibrillation, low mood or unexplained weight loss with none of the classic agitation.

In Graves' disease the eyes may be involved: gritty, watering, protruding, with double vision in more severe cases. Smoking makes eye disease significantly worse, and stopping is one of the few things that genuinely changes its course.

Finding the cause, before treating

Graves' disease is autoimmune, affects the whole gland, and is confirmed by TRAb antibodies. A toxic multinodular goitre or a single toxic adenoma is a nodule or nodules working independently of the pituitary. Thyroiditis — after a viral illness, after childbirth, or from amiodarone — releases stored hormone from a damaged gland and is temporary. Excess thyroxine, whether prescribed or taken for weight loss, produces the same picture from outside the body.

The distinction is not academic. Antithyroid drugs work in Graves' disease and in toxic nodules; they do nothing in thyroiditis, where the gland is not overproducing but leaking, and the treatment is a beta blocker and time. A radionuclide uptake scan separates these when antibodies and ultrasound leave it unclear.

The treatment options, ranked

Antithyroid drugs first, in most cases. Carbimazole is the standard; propylthiouracil is preferred in the first trimester of pregnancy and reserved otherwise because of a rare risk of liver injury. A course of twelve to eighteen months puts a meaningful proportion of Graves' disease into lasting remission. A beta blocker is usually added at the start to control heart rate and tremor while the antithyroid drug takes several weeks to work.

Radioiodine second, where drugs fail or the disease relapses, or for a toxic nodular goitre where remission is not realistic. It is a drink, not an operation, and it is effective. It usually results in permanent hypothyroidism needing lifelong thyroxine — which is a straightforward trade, not a complication. It is absolutely contraindicated in pregnancy and breastfeeding, requires contraception for a period afterwards, and can worsen active Graves' eye disease.

Surgery third, and the right answer in specific situations: a large goitre pressing on the windpipe, a coexisting suspicious nodule, severe eye disease, or when a rapid and definitive result is needed. It requires an experienced surgeon; the risks are to the voice and to the parathyroid glands.

Which of these suits you depends on your age, whether you are planning a pregnancy, the size of the gland, whether your eyes are involved, and what you can realistically attend for. We will go through the three in your particular situation rather than presenting one as the default.

Monitoring while on treatment

Free T4 and free T3 guide the early dose changes; TSH stays suppressed for months after the hormones normalise, so a TSH checked too early will tell you nothing useful. Liver function and a full blood count are checked before starting and if symptoms suggest a problem.

The dose is reduced as the gland responds. Overshooting into hypothyroidism is common and easily corrected — but only if you are being tested, which is why the review schedule is not optional on this treatment.