Before we get to understanding Hypothyroidism, let us first understand the normal functioning of thyroid gland:

The thyroid is a butterfly-shaped gland situated in the front of the neck and it weighs about 20-25 gms in an adult person. This gland takes up the iodine from the foods we eat and converts it into hormones namely Thyroxine (T4), Tri-iodothyronine (T3) Calcitonin. These hormones affect growth and development and also control the way body utilizes energy. The levels of thyroid hormones are in turn controlled by TSH (Thyroid stimulating hormone/ Thyrotropin) that is secreted by the pituitary gland situated in the brain.

About hypothyroidism:

Hypothyroidism is a condition in which less than normal levels of thyroid hormones are circulating in the blood. This can be due to a problem with the thyroid gland itself (Primary hypothyroidism) wherein it cannot produce sufficient hormones due to certain reasons or due to a problem with the pituitary gland (Secondary hypothyroidism) wherein the basic stimulus for the hormone secretion is lacking. In either case, the end result is that there are widespread consequences on the whole body due to lack of T3 and T4 hormones.

Normal hormone levels:

T3 (Tri-iodothyronine): 80-220 nanograms/dl

T4 (Thyroxine): 4.5 to 12.5 micrograms/dl

TSH (Thyroid Stimulating Hormone): 0.5-6 micro International units/ml

Almost 3-5 % of the world population suffers from hypothyroidism, the incidence being much higher in women (almost 10%). The incidence increases with age. This is one of those conditions which sometimes exist for many years before being diagnosed and treated properly.

Anyone can get hypothyroidism though it tends to affect older adults especially women above the age of 50 years. The condition can even affect infants and can present in a severe form known as Cretinism.

Due to its inherent nature, the condition tends to be very subtle in the initial stages and can often be missed for ageing or symptoms of menopause. However, the good news is that sufficient and precise tests are now available for diagnosing it thus paving a way for timely treatment.