The Thyroid is an endocrine gland present in the neck of every human being. It is a very important gland which is essential for life. Thyroid gland produces two important hormones known as Thyroxine (T3) and levothyroxine (T4) which are responsible for maintaining human metabolism. In other words hormones produced by thyroid glands are essential for breakdown of nutrients we consume to produce energy required for normal body functioning. One more hormone known as Thyroid stimulating hormone (TSH) is produced by a tiny gland in the brain known as pituitary gland which controls thyroid gland to produce required amount of thyroid hormones. Normal levels of all these hormones are very essential for normal human metabolism.
The thyroid gland is situated in the lower part of our neck. It is a butterfly shaped structure which wraps around the trachea (wind pipe). It is very richly supplied by blood vessels which explains the importance of thyroid gland to our body. In a normal individual thyroid gland is not visible externally and cannot be felt by hands. Any increase in size of the thyroid gland makes it visible externally and then it can be felt by our hand. When thyroid is enlarged it is known as Goitre.
In day to day clinical practice it is apparent that people have lot of misconceptions regarding thyroid. In fact it is common to see patients telling ‘I have thyroid!’ This article intends to remove those misconceptions and give more information to general population regarding thyroid related diseases. Thyroid gland can be involved by many diseases some common and some rare.
This article will cover only commonly encountered thyroid diseases.
- Hypothyroidism: This is the most common disorder of the thyroid gland affecting large number of people. When thyroid gland fails to produce enough of thyroid hormones to satisfy requirement of our body then we call it has hypothyroidism. Causes of hypothyroidism are many such as iodine deficiency, after thyroid surgery, thyroiditis, after radiation therapy etc. Many times no cause can be identified then it is known as idiopathic. Symptoms of hypothyroidism are generalized weakness, unexplained weight gain, constipation, dry skin, menstrual disturbances, intolerance to cold, infertility and change in voice. If you have these symptoms you need to undergo blood tests to confirm the diagnosis. Commonly performed thyroid tests are Free T3, Free T4 and TSH hormone levels comprehensively called as Thyroid function tests. Ultrasound of the neck is sometimes necessary to look for thyroid swelling or thyroid nodules. Once the diagnosis of hypothyroidism is made the treatment is simple and very effective. A single pill of levothyroxine needs to be taken every day at least half an hour before breakfast. You need to consult a specialist to prescribe appropriate dosage for your hormone level. Repeated tests may be required every few months for initial dosage adjustments. Levothyroxine is safe and devoid of major side effects. One need not worry about daily levothyroxine pills as they are proven to be effective long term follow ups shown it to be extremely safe. Surgery is not indicated in hypothyroidism unless thyroid is very enlarged and patient is concerned about the neck cosmesis.
- Hyperthyroidism: This condition is less common compared to hypothyroidism. In this condition thyroid gland produces excessive amount of thyroid hormones. Most common cause for hyperthyroidism is Grave’s disease. In hyperthyroidism symptoms are unexplained weight loss in spite of eating adequate amount of food, excessive sweating, palpitation (feeling your own hear beat), loose stools, tremors of hands (Shaky hands), prominent eye balls, intolerance to heat etc. Diagnosis is usually done by thyroid function tests where in raised levels of T3 and T4 are seen with significant decrease in TSH levels. Once diagnosed treatment includes daily consumption of anti-thyroid drugs. Treatment may have to be taken for many years before your physician decides to give a trial of stopping the medicines. Other option for treatment of hyperthyroidism is radio Iodine therapy. A single sitting or sometimes few sittings are necessary. This treatment gives permanent cure and daily medicines are not required. Radio iodine therapy facility is available in only few centers and big hospitals and it has initial high cost. Surgery is usually avoided in hyperparathyroidism due to associated major complications during surgery. Only patients who does not respond to ant-thyroid drugs and where radio iodine treatment is not available surgical option can be given.
- Benign Thyroid nodule: Thyroid is a very common site for small to big nodules or swellings. Sometimes nodules are small not be appreciated externally and sometimes big to be seen externally. Most of the thyroid nodules are benign (Non-Cancerous). With common availability of ultrasound facilities it is easy to identify small thyroid nodules which used to be undiagnosed in earlier days. Once they are identified it is necessary to undergo Fine needle aspiration cytology (FNAC) where a needle is passed inside the nodule and sample is collected to be examined by a pathologist. This test is sensitive enough to diagnose if it’s a cancerous nodule or benign nodule. Along with FNAC ultrasound of neck and thyroid function tests may be necessary. A diagnosed benign thyroid nodule does not warrant any treatment. Patient needs to counseled regarding benign nature of the swelling and surgery is done only if nodule is big enough to cause cosmetic concern to the patient. It is very rare to see benign nodule changing into a cancer.
- Thyroid cancer/ Thyroid malignancy: incidence of thyroid cancers are rapidly increasing throughout the world compared to any other cancers. Fortunately thyroid cancers have the best outcome if appropriately treated. Most of the patients who are treated for thyroid cancer will complete their normal life span. It is very rare to see patients dying of thyroid cancers even if diagnosed in advanced stages. Diagnosis of thyroid cancer is done using FNAC. Treatment of diagnosed thyroid cancers is surgical and most of the patients will require surgical procedure known as total thyroidectomy. Patient needs to be under frequent follow up after the initial treatment. If patient follows surgeon’s instructions he can lead his normal life.
- Pubertal goitre/Physiological Goitre: It is very common to see young girls in their pubertal age developing thyroid swelling. One has to understand that puberty in girls leads to physiological stress to body. At puberty there is need for increased metabolism so is the need for thyroid hormones. This leads to increased production of TSH from the pituitary gland which makes the thyroid gland to increase its size to cope up for urgent need for more thyroid hormones. Diagnosis is usually done by thyroid function test and clinical examination. Treatment with thyroid replacement with levothyroxine is done only in cases with significant changes in hormone levels. If necessary low dose of levothyroxine for few months may be necessary. Most of the patients with pubertal goitre recover spontaneously.
- Hashimoto’s Thyroiditis: This is a peculiar disorder of thyroid gland grouped as auto immune thyroid disease. In this condition our own body produces certain antibodies against our own thyroid gland leading to slow destruction of thyroid gland. Initially patient may have symptoms of hyperthyroidism with thyroid swelling. Eventually hypothyroidism sets in and most of these patients will become permanently hypothyroid. This condition is treated as regular hypothyroidism.
- Thyroid cysts: Some people may develop sudden onset of thyroid swellings within matter of days to months. Ultrasound of neck may reveal water filled cysts inside the thyroid gland. Most of these cysts are benign and if small can be left untreated. If cysts are big enough to cause concern to the patient then ultrasound guided aspiration using a needle may be considered. If cysts recur after multiple aspirations then surgery in the form of removing part of the thyroid gland (hemithyroidectomy) may be the only option
Person diagnosed with any of the thyroid related diseases should consult specialist who regularly deals with thyroid disorders. Usually ENT and Head and Neck surgeons, Physicians, Endocrinologists, General Surgeons are trained in treating these conditions. One has to know that except for thyroid cancers none of the other conditions mandate surgery. All other conditions other than cancers can be managed with medicines and indication for surgery in such conditions is mainly cosmetic.