The thyroid is a gland that is found in the neck area. It can cause problems in many people throughout their lives. It can become enlarged, infected, inflamed, cancerous, subject to autoimmunity and this can cause body wide effects via imbalance of the thyroid hormone. Two common conditions include hypothyroidism and hyperthyroidism - these conditions involve too little or too much circulating thyroid hormones and cause many problems in the body.
Symptoms arise from abnormal levels of thyroid hormone and are very variable. They include problems with hair loss, cognition, mood, energy levels, heart rate, body temperature, weight change, menstrual cycle, joint and muscle pain and weakness, tremors, change of bowel habit and sleep disturbances. In some conditions, the thyroid gland can become enlarged and noticeable on physical examination - this is called a goitre.
The thyroid can be subject of many pathologies. The commonest problem is related to autoimmune disease. Other problems can result when the thyroid becomes infected and inflamed. Thyroid cancer is a common endocrine cancer and the treatment can render patients hypothyroid for the rest of their lives. Problems with the levels of thyroid hormones can sometimes originate from other parts of the body which have a role in stimulating the thyroid. Tumours in certain parts of the brain can cause deficiency in the amount of thyroid stimulating hormone; here, the thyroid itself is normal. Iodine deficiency can cause problems with the creation of the hormones and this is usually from lack of iodine in the diet. This is common in third world countries and is rarer in the UK, however it does occur.
The treatment for thyroid disorders depends exactly on the cause.
If the thyroid is underactive or if there is a deficiency of the thyroid hormone, it can be replaced with an artificial version of the hormone called levothyroxine. Patients can be on this medication for life and with the right dosage, it is very good at controlling symptoms.
If the thyroid is overactive and there is therefore too much thyroid hormone in the body, treatments available include radioactive iodine therapy. This involves injecting radioactive iodine, which is then taken up by the thyroid and when this occurs, it destroys some or all of the gland, depending on the dosage. In severe hyperthyroidism or in cancer, the thyroid gland can be removed surgically. The patients then receive levothyroxine for the rest of their lives.