Thyroid gland is situated in the lower part of the neck, which produces the thyroid hormones that control the rate of metabolism. In short, our mental and physical growth are dependent on this gland. The thyroid is in turn controlled by the pituitary gland located at the bottom of the skull, which produces thyroid stimulating hormone.

T3 (Triodothyronine) and T4 (thyroxine) are the main thyroid hormones. Any swelling or under/over activity of this gland can affect the body in disturbing ways.

Hyperthyroidism, and hypothyroidism are the two most common types of thyroid diseases relevant to hair loss. Studies show that these diseases are commonly found in women.

The overproduction of thyroid hormone which diffuses hair loss is termed as hyperthyroidism. Graves' disease is the most common cause of hyperthyroidism. Usually, women between the age group of twenties and thirties are mostly infected with this problem. Hypothyroidism, on the other hand, is a condition that doesn't produce enough thyroid hormone. Hashimoto's disease is the most common cause of hypothyroidism.

Although, both the diseases show similar signs and symptoms, yet there are some differences. Hyperthyroidism results in loose bowel movement whereas hypothyroidism results in constipation.

Patients suffering from hyperthyroidism are more tolerant towards heat. Whereas, patients suffering from hypothyroidism are more tolerant towards cold. Hair loss is a common sign in both these types of thyroid diseases.

Common symptoms of Hyperthyroidism are:

• Weight gain or loss
• Excessive perspiring
• Fatigue
• Leg swelling
• Emotional changes
• Oily skin.

Common symptoms of Hypothyroidism are:

• Weight gain
• Depression
• Swelling of eyelids, hands and feet
• Muscle aches
• Dry skin.

In the recent years, studies show that millions of Americans have been affected with some or the other thyroid diseases. Hence, you should consult a doctor if you have unexplained hair loss or a thyroid issue.