When thyroid disease runs in the family

How to tell — and what to do —if you or your family members are at risk

When businesswoman Iris Lee (not her real name), 35, noticed that she was losing weight despite not being on a diet, she thought it was too good to be true. And it was. Along with her weight loss, her neck had also started to swell and her hands were constantly trembling. Iris also found herself fidgety, anxious and had a pulse rate of about 100 beats per minute, compared to the average of about 72 beats per minute. These were possible signs of thyrotoxicosis, where the body produces too much thyroid hormones.

The commonest cause is Grave’s disease. In this condition, the body automatically produces auto-antibodies that target the patient’s own body instead of external invaders. In Iris’ case, it stimulated her thyroid gland, causing it to overproduce thyroid hormones, causing a condition known as hyperthyroidism. When thyroid levels are high, the body’s metabolic rate increases and symptoms like unintended weight loss and hyperactivity occur. There could also be heat intolerance, sweating, hair loss, anxiety, diarrhoea and menstrual irregularities. In addition the antibody might also target the tissues behind the eyes and hence cause the eyes to protrude.

In Singapore and Asia, medication is the most common choice of initial treatment and patients are typically treated for about 18 months. However, hyperthyroidism may return when treatment is stopped, especially if one has a big thyroid gland or high levels of antibodies. Iris’s diagnosis was confirmed through a blood test. She was treated with the drug methimazole, which she took once a day, alongside with a beta-blocker that helped decrease her rapid heart rate.

Common occurrences

Auto-antibodies directed against the thyroid are common, especially among women, and can cause hyperthyroidism or hypothyroidism, the underproduction of thyroid hormones. Among the two conditions, hypothyroidism is more common —up to five per cent of the population has it —and the risk of the disease increases with age. Moreover, thyroid disorders commonly run in the family.

Iris’ older sister, Ivy, 43 years of age, had also found herself experiencing symptoms that seemed to be the opposite of her sister’s. She was gaining weight despite regular exercise and found it hard to concentrate at work. Her menstrual cycle was also affected with frequent and heavy periods.

A blood test showed that she did indeed have low thyroid hormones and she also had auto-antibodies in her blood, but of a different type from her sister’s. In her case, the antibodies that were produced destroyed her thyroid cells, causing hypothyroidism. Ivy was promptly treated with replacement of her thyroid hormone with thyroxine. Today, the two sisters are back to their usual energy levels and regular lifestyles.

Don’t ignore the warning signs

Thyroid disorders caused by autoimmune abnormalities can be treated effectively. If you notice any signs and symptoms of hypothyroidism or hyperthyroidism, do not ignore them.

If you suspect a thyroid disorder, seek medical help as soon as you can. Be honest with your doctor, go for tests if necessary and seek treatment early. Early detection and treatment can prevent the condition from worsening and possibly leading to unwanted consequences on your health.