Abnormal hormones are often blamed for loss of scalp hair though, perhaps surprisingly, they are responsible for just a small minority of instances of this distressing symptom. Many different conditions can lead to Hair Loss; some hair loss is part of normal life. Women after childbirth and at the time of the Menopause can lose hair and almost every man will lose some hair by the time of reaching adulthood. Elderly males and females will develop baldness of various degrees, which is largely determined by genetic factors.

Human scalp hair does not grow continuously. Every hair follicle (the unit of hair production) undergoes phases of growth, during which hair lengthens, followed by a period of rest (the telogen phase). During telogen, the hair is shed and replaced by a new hair. In some animals this process is synchronised; that is why dogs lose a lot of hair at the same time or "moult". Human hair growth is not coordinated in the same way, so at any one time different hair follicles are at different stages of their growth cycle. So, it is normal to have some ongoing continuous hair loss, which usually is balanced by new hair growth. One of the commonest causes of hair loss is called "telogen effluvium". This can be triggered by any severe illness, for instance pneumonia or a major operation. The stress of the illness causes all hair follicles to go into their resting phase and hair growth temporarily ceases. Because the human hair cycle is long (several months), the hair loss may not become apparent for several months, by which time the person will have recovered from their illness. Such hair loss also coincides with new hair beginning to regrow and therefore the hair loss is transient.

Hair loss and thyroid disease
Severe and prolonged hypothyroidism and hyperthyroidism can cause loss of hair. The loss is diffuse and involves the entire scalp rather than discrete areas. The hair appears uniformly sparse. Regrowth is usual with successful treatment of the thyroid disorder, though it will take several months and may be incomplete. It is unusual for mild (e.g. subclinical) hypothyroidism or hyperthyroidism, or short-lived thyroid problems to cause hair loss.

Some forms of Hypothyroidism and Hyperthyroidism come on abruptly and are diagnosed early, while others may have been present for months or years before diagnosis. Hair loss due to thyroid disease becomes apparent several months after the onset of thyroid disease. This is due to the long hair cycle. In such cases, paradoxically the hair loss may follow the treatment for the thyroid and the thyroid medication may be erroneously blamed, leading to withdrawal of treatment, which in turn may worsen the hair loss.

Diet for Thinning Hair
There is no specific diet that you can follow, for thicker hair. However, it is a well-known fact that a nutritious diet can help improve the overall health. A healthy diet also reduces nutritional deficiencies, which in turn could eliminate severe hair fall problems. Given below are some of the foods that are the most effective for reducing hair loss and thinning problems:

-- Iron rich foods like prunes, raisins, oysters, liver, mussels, kidney, beans, lean beef, spinach and lentils.
-- Good sources of protein, such as eggs, chicken, turkey, soybean, tofu, soymilk, fish, low fat cheese and yogurt.
-- Silica, a nutrient that increases the collagen in the body, which is found in seeds, cereals, oats, fish, pumpkin, onions, peanuts, raisins, tomatoes, apples, nuts, honey, carrots, raw cabbage, almonds, cherries and oranges.
-- Zinc, an essential nutrient, which is usually present in peanuts, mutton, squash seeds, pumpkin, lean beef, tahini, sesame seeds, veal, liver, wheat germ and oysters, to name a few
-- Vitamin, which is found in legumes, potatoes, brazil nuts, oats, beef, avocadoes, bananas, turkey, tuna and liver.