What is a thyroid gland?
A thyroid gland is an endocrine gland; this means that it manufactures hormones that are released into the bloodstream,which then act as messengers to affect cells and tissues in other parts of thebody.
Where is the thyroid gland?
The thyroid gland lies on either side of your windpipe, with the gland as a whole lying just below your Adam's apple.
What does the thyroid gland do?
The thyroid gland produces thyroid hormones which it secretes into the bloodstream.If hormone production is insufficient, it can easily be replaced with medication.
What do the thyroid hormones do?
Thyroid hormones regulate the speed at which your body cells work. If too much of the thyroid hormones are secreted, the body cells work faster than normal, and you have thyroid overactivity or 'hyperthyroidism' (also referred to as "thyrotoxicosis").However if too little of the thyroid hormones are secreted then the body cells work slower than normal and you have underactivity or 'hypothyroidism'.
How is the thyroid gland controlled?
Thyroid gland works in conjunction with pituitary, which lies underneath your brain in your skull and senses the levels of thyroid hormones in your bloodstream. If the levels drop below normal, the pituitary reacts by secreting a hormone called the 'thyroid stimulating hormone' which is often called TSH. TSH stimulates the thyroid gland to make more thyroid hormones. Should the thyroid hormone levels rise above normal for example in Graves' disease), the pituitary senses this and slows down or stops making TSH.
How is thyroid activity measured?
Your doctor will be able to get a good assessment of your thyroid gland activity by taking a history of your symptoms and by a physical examination. However, to gain an exact level of the thyroid hormones, it is necessary to take a small sample of blood, which when analysed in the laboratory will show how much T4 is being made, and how active your pituitary is, by measuring the level of TSH. These tests are sometimes called thyroid function tests or TFTs.
How is thyroid disease diagnosed?
Thyroid disease can fall under numerous disease entities. Your illness may be due to under or over functioning of the gland or even you could be having a disease where the function of the gland is normal. Treatment depends on the particular disease of thyroid you are suffering from. Your doctor will order necessary investigations as to pin point the diagnosis (TFT, thyroid antibody profile, Ultrasound scanning of neck, FNAC, Nuclear imaging) and then decide on the treatment.
How do I suspect hypothyroidism (under functioning of thyroid)?
Common complaints include fatigue and lethargy, cold sensitivity, dry skin and lifeless hair, impaired concentration and memory, increased weight with poor appetite and constipation. Patients may also fairly often experience a hoarse voice, tingling of the hands (carpal tunnel syndrome), heavy and later, absent periods, deafness and joint aches. In childhood there may be delayed development and in the adolescent early onset of puberty.
The elderly may develop memory disturbances,an impaired mental state or depression, and in rare cases coma can occur, resulting in death if left untreated. Signs include slow movements,face looks puffy due to the accumulation of subcutaneous fluid, cool dry skin, slow pulse rate, thinning of the hair including the eyebrows,slow tendon reflex relaxation time, slow pulse rate and hoarse voice. The thyroid may be enlarged (causing a goitre) in some patients due to accumulation of lymphocytes (Hashimoto's thyroiditis), but in others the thyroid is destroyed by the time of diagnosis and there is no goitre.
Nowadays patients often are diagnosed at an early stage of disease, due to increased awareness and improved biochemical testing. Therefore many patients have relatively few of the classical signs or symptoms just listed. In addition, none of the symptoms or signs are sufficiently sensitive or specific for the diagnosis of hypothyroidism, even when combined together.
How do I suspect hyperthyroidism (over functioning of thyroid)?
Common complaints include fatigue, heat intolerance,sweating, weight loss despite good appetite, shakiness, inappropriate anxiety, palpitations of the heart, shortness of breath, tetchiness and agitation, poor sleep, thirst, nausea and increased frequency of defecation. The elderly may complain predominantly of heart problems with a fast or irregular heart beat, breathlessness and ankle swelling,whereas children tend to have hyperactivity, with a short attention span.Signs include shaky and hot hands, fast or irregular heart beat,inability to sit still, flushing of the face, an enlarged thyroid gland and prominent or bulging eyes. Nowadays patients often are diagnosed at an early stage of disease, owing to increased awareness and improved biochemical testing. Therefore some patients have relatively few of the classical signs or symptoms. In addition, none of the symptoms or signs just listed is sufficiently sensitive or specific for the diagnosis of hyperthyroidism, even when combined together. It is not uncommon for people to worry that they have cancer, because of the associated weight loss.
When do I get evaluated for thyroid cancer?
Often thyroid cancers do not produce symptoms and is found by chance. But still it is one cancer that we need to be aware of as most thyroid cancers are very treatable and curable. You may need to get evaluated for thyroid cancer if you have any of the following symptoms:
A painless lump in the neck which gradually increases in size.
Enlarged thyroid or nodule in the region of thyroid with:
Difficulty in swallowing
Difficulty in breathing
Hoarseness of the voice
How is thyroid disease treated?
Treatment depends on the diagnosis. It can vary from oral tablets to radioactive iodine treatment to surgery as on a case to case basis. Many goiters such as the multinodular goiter are associated with normal levels of thyroid hormone in the blood. These goiters usually do not require any specific treatment after the appropriate diagnosis is made.
How long do I need to take treatment?
Again it depends on diagnosis. It can be a few months as in case of viral thyroiditis. If the goiter is due to Hashimoto's Thyroiditis, and you are hypothyroid, you will be given thyroid hormone supplement as a daily pill. This treatment will restore your thyroid hormone levels to normal, but does not usually make the disease go away.So you may have to take treatment lifelong so as to keep your hormone levels in normal range.
How is thyroid disease important in Pregnancy?
For the first 10-12 weeks of pregnancy, the baby is completely dependent on the mother for the production of thyroid hormone. By the end of the first trimester, the baby's thyroid begins to produce thyroid hormone on its own. The baby, however,remains dependent on the mother for ingestion of adequate amounts of iodine, which is essential to make the thyroid hormones. Untreated orinadequately treated, hypothyroidism has been associated with maternal anemia (low red blood cell count), myopathy (muscle pain, weakness),congestive heart failure, pre-eclampsia, placental abnormalities, low birth weight infants, and postpartum hemorrhage (bleeding).
Recent studies have also suggested that mild brain developmental abnormalities may be present in children born to women who had mild untreated hypothyroidism during pregnancy on the other hand,uncontrolled maternal hyperthyroidism has been associated with fetal tachycardia (fast heart rate), small for gestational age babies,prematurity, stillbirths and possibly congenital malformations.So,ifyou have thyroid disease, it is advisable to get an endocrinology opinion prior to planning pregnancy and to monitor thyroid function regularly through gestational period.
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