Understanding thyroid health

In his latest online article, Dr Umasuthan Srirangalingam gives us his insights into thyroid health. He talks about what the thyroid gland does, the common symptoms and how to maintain a healthy thyroid.

What does the thyroid gland do?

The thyroid is a gland which sits in front of your voice box in the neck, just below the ‘Adam's apple.’ It produces two main hormones, thyroxine (T4) and triiodothyronine (T3), which play an important role controlling your metabolic rate, or put simply - how quickly everything in your body works. Thyroid hormones work across many organs and so when the thyroid is not working, it can affect many systems in the body.

Thyroid function is controlled by an intricate feed-back loop with the pituitary gland found in the brain.  The pituitary gland detects the level of T4 and T3 in the blood and varies a signal, thyroid stimulating hormone (TSH) to ensure levels remain stable. TSH stimulates the thyroid gland to produce T4 and T3.

Some of its key functions of the thyroid gland in addition to regulating your overall metabolism include; energy balance; controlling body temperature; cardiovascular function including your heart rate and blood pressure; muscle strength; digestive tract and bowel function; bone health; menstrual cycle and fertility in women; mood and cognitive function.

What are the common symptoms of thyroid disorders?

There are three main disorders affecting the thyroid gland. The gland can be overactive (hyperthyroidism), it can be underactive (hypothyroidism) or a nodule or lump can be found in the thyroid. You may hear a number of terms being used in relation to the thyroid gland. A ‘goitre’ is an enlarged thyroid gland. Thyroiditis is a general term used when the thyroid gland is inflamed. The causes of this inflammation can be varied. Grave’s disease is inflammation in the thyroid gland caused by antibodies which make the thyroid overactive. Hashimoto’s thyroiditis is inflammation in the thyroid gland caused by antibodies which generally make the thyroid underactive. Other forms of thyroiditis can be seen after pregnancy or following an infection.

When the thyroid gland is underactive (hypothyroidism) everything, in general, slows down. Common symptoms include feeling tired or lethargic; feeling the cold more than usual; gaining weight or finding it difficult to lose weight; dry or puffy skin; low mood; poor memory and ‘brain fog’; constipation; in women, periods can be heavy or irregular and fertility may be an issue. The thyroid gland may or may not be enlarged. There are a number of different causes of hypothyroidism.

When the thyroid gland is overactive (hyperthyroidism) everything, in general, speeds up. Typical symptoms can include feeling nervous; tremor; losing weight; sweating; having endless energy but can paradoxically also be associated with fatigue; In women, again periods can become lighter, irregular or can stop. Thyroid enlargement may also occur.

In Grave’s disease some people can get involvement of the eyes, experienced as grittiness, prominence of the eyes or changes in vision. Again, there are a number of different causes of hyperthyroidism.

A person with a thyroid nodule or enlarged thyroid gland may note a lump in the neck; someone else might comment on it; some may note difficulties swallowing, shortness of breath or noisy breathing.

Many symptoms of thyroid disease are non-specific e.g., non-hormonal causes also possible, and so it can sometimes be difficult to recognise a disorder. It would be important to establish the person’s thyroid status, and if abnormal, the cause. This can be established by an endocrinologist taking a detailed history and examining a patient. A blood test and often an ultrasound of the thyroid gland is enough to establish the diagnosis. Some patients need a sample taken from the thyroid gland to be examined under the microscopic to establish the diagnosis. This is called a fine need aspirate (FNA). Commonly medication can be used to treat an overactive thyroid gland (carbimazole and propylthiouracil (PTU)) or underactive thyroid gland (mostly thyroxine). Some patients choose to replace with liothyronine (T3) or natural desiccated thyroid (NDT) extract from animal sources. Thyroid nodules are either left alone (benign), monitored over time or removed (partial or total thyroidectomy). Thyroid cancers can occur but these are, in general, readily amenable to treatment.

How can I maintain a healthy thyroid?

Maintaining a healthy lifestyle: a balanced diet, exercising and managing stress are good strategies to optimise hormonal health in general. No specific diet modification is recommended to treat thyroid disease.

Iodine is essential for normal functioning of the thyroid gland and requirements do increase in pregnancy. In some regions of the world iodine intake in the diet is low and this can lead to thyroid disorders, but in the UK, this is not an issue. Common sources of iodine are dairy products and fish. Salt can have iodine added to it. But iodine supplementation is not routinely recommended and can in some cases be actually detrimental to treating thyroid disease.

Selenium plays a role in maintaining normal thyroid function. Selenium intake should be sufficient with a normal healthy diet. Supplementation has been shown to help in patients with thyroid eye disease related to Grave’s but is not recommended for other thyroid disorders.

If you do take thyroid replacement it is important to be aware that some medications can interfere with the absorption of thyroid hormone. Thyroid hormone should be taken on an empty stomach, not with food and separate from iron or calcium supplements which all can reduce absorption. Biotin, the B vitamin, if taken in high doses can make thyroid tests unreliable and so should be stopped prior to checking thyroid function.

Dr Umasuthan Srirangalingam is a distinguished endocrinologist with over 20 years of experience. You can a schedule an appointment with Dr Srirangalingam on his Top Doctors profile.