Graves' disease: symptoms, eye problems, treatment and pregnancy

Graves' disease causes the symptoms of an overactive thyroid. The NHS says these can include a wide range of symptoms, although it is unlikely you will experience all of them. They may develop gradually or suddenly, and are mild for some people and severe for others.

The NHS explains that an overactive thyroid (hyperthyroidism) is where the thyroid gland produces too much of the thyroid hormones. The thyroid is a small butterfly-shaped gland in the neck that produces hormones that affect things such as your heart rate and body temperature.

Graves' disease is the most common cause. It is an autoimmune condition where the immune system produces antibodies that cause the thyroid to produce too much hormone. The NHS says other causes include lumps (nodules) on the thyroid, medicines such as amiodarone, thyroiditis and high levels of the pregnancy hormone hCG.

The NHS says eye problems, known as thyroid eye disease or Graves' ophthalmopathy, affect around 1 in 4 people with an overactive thyroid caused by Graves' disease. The British Thyroid Foundation (BTF) describes thyroid eye disease (TED) as an autoimmune inflammatory disorder that affects the orbit of the eye, and says early diagnosis is essential for treatment to be effective and that people with TED need to be looked after by an eye specialist and a thyroid specialist.

The NHS says many people have mild eye symptoms that get better as the overactive thyroid is treated, but some continue to have problems, and severe disease can cause vision loss. If you have eye problems you may be referred to an ophthalmologist for treatment such as eye drops, steroid medicine or possibly surgery. The BTF says that smoking increases the risks.

• Eyes feeling dry and gritty.

• Sensitivity to light and watering eyes.

• Blurred or double vision.

• Red eyes and red, swollen or pulled-back eyelids.

• Bulging eyes.

The NHS says an overactive thyroid is usually treatable, and you will usually be referred to an endocrinologist who will plan your treatment. Each treatment has benefits and drawbacks.

The NHS says that during the first couple of months some people experience side effects such as feeling sick, a high temperature, headaches, aching joints, altered taste, upset stomach or an itchy rash, which should pass as your body gets used to the medicine.

A less common but more serious side effect is a sudden drop in white blood cells (agranulocytosis), which can make you very vulnerable to infections. The NHS says to contact your doctor immediately if you get symptoms such as a high temperature, sore throat or a persistent cough, as they may arrange a blood test.

The NHS says it is very important to use contraception if you are taking carbimazole or have had radioactive iodine treatment in the last 6 months, because both can harm an unborn baby. Tell your doctor immediately if you are planning a pregnancy or become pregnant while taking carbimazole or after radioactive iodine treatment within the past 6 months.

The NHS says that if you have an overactive thyroid during pregnancy and it is not well controlled, it can increase the risk of pre-eclampsia, miscarriage, premature labour and birth and a low birthweight baby. Your doctor will want to check your condition is under control and, if you are taking carbimazole, may recommend switching to propylthiouracil.

After radioactive iodine treatment, the NHS says women should avoid getting pregnant for at least 6 months and men should not father a child for at least 4 months.

The NHS says diagnosis is based on your symptoms and a blood test (a thyroid function test) that checks levels of thyroid-stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4). A low level of TSH and high levels of T3 and/or T4 usually means you have an overactive thyroid.

If hormone levels are high, you may be referred to a specialist for further tests to find the cause. The NHS says these may include a blood test for anti-thyroid antibodies, which are usually found if you have Graves' disease, an ESR test to look for inflammation (which would point to thyroiditis) and a thyroid scan to look for nodules.

The NHS says several complications can develop if you have an overactive thyroid, particularly if it is not treated. As well as eye problems and pregnancy problems, it can increase the chance of atrial fibrillation, weakened bones (osteoporosis) and heart failure. Radioactive iodine often causes an underactive thyroid, which may be temporary but is often permanent and needs long-term thyroid hormone medicine.

The NHS says that rarely an undiagnosed or poorly controlled overactive thyroid can lead to a thyroid storm, a sudden, life-threatening flare-up of symptoms triggered by an infection, pregnancy, not taking medicine correctly or damage to the thyroid. Symptoms include a rapid heartbeat, a high temperature, high blood pressure, jaundice, severe agitation and confusion and loss of consciousness. It is a medical emergency, and the NHS says to call 999 for an ambulance immediately.

The NHS pages on an overactive thyroid do not set out a specific diet for Graves' disease. The NHS says an increased level of iodine in the body can cause the thyroid to produce excess hormones, which can occasionally happen with medicines that contain iodine, such as amiodarone. Ask your endocrinology team or GP before taking supplements, and say if you take any medicine containing iodine.

Smoking increases the risk of Graves' disease and, according to the BTF, the risk of thyroid eye disease, so stopping smoking is an important step.

On the NHS, a GP arranges thyroid function tests and refers you to an endocrinologist for further tests and treatment. People with eye problems may be referred to an ophthalmologist, and the BTF notes that access to specialist joint thyroid eye clinics varies across the UK.

Some people choose a private endocrinology consultation for quicker review or to discuss treatment options. Anti-thyroid medicines need regular blood monitoring, and radioiodine and surgery involve specific precautions, so make sure your GP and NHS team are aware of any private treatment.