The thyroid gland is located in front of the neck. It is a butterfly-shaped gland. It has two lobes on either side of the windpipe. It serves a number of important functions in the body. The thyroid hormone secreted by the thyroid gland circulates all over the body. In childhood, it is responsible for the proper growth and development of the brain. Children born with hypothyroidism, if they are not diagnosed early, become mentally retarded. It also affects their growth. Thyroid diseases affect every organ in your body.
Common thyroid disorders are hypothyroidism, hyperthyroidism and swellings of the thyroid glands which are called goitre. Thyroid disorders are more common in women than men.
The test being done.
HYPOTHYROIDISM
Hypothyroidism is the under-functioning of the thyroid gland. Thyroid hormone levels will get reduced in the individual. Hypothyroidism may sometimes be very silent, may not have many symptoms. But it can present with a variety of symptoms including weight gain, lethargy, tiredness, loss of memory, depression, and loss of hair from the head. It can also cause constipation and dryness of the skin. Hypothyroidism troubles women with menstrual irregularities. While some women experience heavy periods, some miss their periods due to this.
Because symptoms of this condition are so varied and common, it is often very difficult to tease out whether it is due to hypothyroidism or not. Many people may say that they experience hair fall, tiredness, depression and constipation at times. About a third of the women population may say that they have some kind of menstrual irregularities. So we can’t attribute all these symptoms to hypothyroidism always. Sometimes hypothyroidism may be picked up only on routine testing. Symptoms may not be obvious if the condition is building up slowly. Hypothyroidism is very common in the elderly.
From a physician’s point of view, symptoms of hypothyroidism are very common in public at large. So, one needs to use some discretion when ordering thyroid function tests. From the patient’s perspective, patients also need to understand that not every person who gains weight or every woman who has menstrual irregularities are hypothyroid. Having said that, if there is suspicion, then the tests should be done. TSH and Free T4 tests will help in diagnosing hypothyroidism. Usually, in hypothyroidism, the free T4 will be low and TSH will be raised.
HYPERTHYROIDISM
Hyperthyroidism is an overactivity of the thyroid gland. In this condition, thyroid hormones are higher than they should be in circulation—as a result of which you get all the opposite symptoms that you get with hypothyroidism. When hypothyroidism causes constipation, in hyperthyroidism one gets diarrhoea or increased frequency of bowel movements. When hypothyroidism makes you lethargic and dull, with hyperthyroidism you get hyper excited and can have shaky hands, restlessness and sweating. A person with hyperthyroidism may become easily irritable, agitated and can have difficulty sleeping. Hyperthyroidism may also cause palpitation—(rapid beating of the heart) and increased appetite. Here, one would observe that despite eating a lot, the weight is coming down. Hair loss and menstrual irregularities are common in both hyper and hypothyroidism.
Hyperthyroidism is relatively easier to diagnose as the patient would present with the feeling of being unwell along with concrete symptoms of hyperthyroidism including weight loss. From the patient’s point of view, anybody who is losing weight rapidly, feeling very shaky, irritable, feeling hot all the time, fatigued should go for a thyroid function test to see whether their symptoms are due to hyperthyroidism. Generally, hypothyroidism is more common than hyperthyroidism.
GOITRE
Enlargement of the thyroid gland is called goitre. When the gland may swell up as a whole, it is called a diffused goitre. Sometimes there may be nodules in the thyroid gland called nodular goitre. The thyroid gland is right in front of the neck; each time you look at the mirror you can easily pick up the swelling of the neck. Generally, people get alarmed when they see swelling in the neck and they present fairly early thinking that it is cancer. One thing we need to keep in mind is that nodules in the thyroid gland are very common. But thyroid cancer is a very rare disease. As clinicians, our challenge is to diagnose a small number of thyroid cancers among the vast number of thyroid nodules. In fact, in a study conducted at Amrita hospital, we found as much as 11 % of the population affected with thyroid nodules are women.
When a patient presents with swelling of the thyroid gland, an ultrasound scan is done to find out the nature of the swelling. Based on the ultrasonography report, if it seems problematic, a fine needle aspiration will tell us the likelihood of that being thyroid cancer or not. If it is completely normal, as it is in majority of cases, then there is no need to rush into surgery. When you have thyroid nodules, there is no need to panic. But it must get suitably evaluated. The vast majority of thyroid nodules is benign and can be followed up over a period of time without the immediate requirement of surgery.
The writer is Clinical Professor and Head, Centre for Endocrinology and Diabetes, Amrita Hospital, Kochi.