Loss of hair becomes excessive during illness. Significant stresses in life causes hair to fall excessively. Moreover when a person develops fever or undergoes a major surgery hair loss is inevitable. During pregnancy daily hair loss does not occur. Following childbirth hair starts to fall excessively which can be seen while combing the hair. Other conditions associated with hair loss include Thyroid disease, severe infections and Systemic Lupus Erythematosus. Ringworm infestation also causes patches of baldness with pink scales.

Children who take large quantities of Vitamin A develop baldness and softening of skull bones followed by development of a swelling called pseudotumour cerebri.

Hair is made up of a protein called Keratin which belongs to the class of Scleroproteins. When some people go on a crash diet or adopt abnormal eating habits the body adapts to conserve its protein content by reversing hair growth to a resting phase. A couple of months later this is manifested by shedding large amounts of hair. However this can be reversed by taking a protein-rich diet. Deficiency of Iron also causes hair loss as seen in women who experience heavy menstrual flow. The male hormone testosterone is responsible for the baldness in males. In women increased hair loss is seen after menopause.

Hair dyes, excessive use of hair dryers, curling irons and styling products are also known to cause hair loss.

In cancer patients following chemotherapy excessive hair loss is seen and they may go bald. This is reversed 3 months following completion of treatment. Some medications used for thinning blood, for treatment of gout, arthritis, acne, psoriasis and some heart problems also cause excessive hair loss. Some women with an inherited hair thinning trait lose hair while on oral contraceptive pills.

Baldness or hair loss is termed alopecia. Hair may be lost in patches as well - the size of a coin or larger - balding progressing backwards from the hairline. This is called alopecia areata. It occurs in either sex at any age - even in childhood. Another variety called androgenic alopecia tends to run in families. A well chosen hairstyle can effectively hide patchy baldness.

It is of interest to note that remedy for hair loss was described in ancient Egypt in the Papyrus Embers which consisted of a concoction of dog's toes, refuse of dates, and ass's hoof. However modern medicine has developed treatments that are effective. The first and foremost approach to managing hair loss is to clear the offending agent. It is said that early treatment prevents hair loss. Minoxidil,Finasteride and injectable steroids such as Triamcinolone are being used with a variable success rate. These are usually available as over-the-counter medications.

Hair transplantation has also helped quite a few to rid themselves of baldness. Hair is harvested from healthy scalp and transplanted to areas of hair loss. In experienced hands transplanted hair appears as though naturally occurring.

There is a lot to learn from Eskimos. They rarely wash the hair. Their diet is not balanced consisting mainly of protein and fats but lacking vitamins. Moreover they apply whale and fish oils to the hair for sheen. The cold temperature causes poor circulation in the scalp which is augmented by wearing of hats and clogging of sebum in the scalp. Despite all these deficiencies the rate of baldness in Eskimos is extremely low.

Moreover wearing additions on the hair causes physical tension and causes the hair to fall. This is called traction alopecia. In a psychological condition called "Trichotillomania" the patient keeps on plucking hairs.

Hair loss is useful in crime detection. Hair falls during physical contact and this is matched with available hair samples by light microscopy. This determines whether hair transfer has occurred.

It is being postulated that humans lost hair during evolution to ward off fur-loving bugs in order to attract the opposite sex. It is interesting to know that apart from humans, elephants, pigs, whales, walruses and the mole-rat also are naked mammals.