"A hair in the head is worth two in the brush" thus said Oliver Herford and he surely realized the worth of every strand. But do we stop to think as to what has resulted in all those extra hair in our hair brush, on the pillow or on the floor of our house? If we know what has caused the hair loss, we can surely take the next step to control the same.

We have already seen that DHT (Dihydrotestosterone) - the male sex hormone - is the primary trigger of male and female pattern baldness. Besides this, more and more hair follicles go into the resting phase with advancing age leading to gradual thinning of hair. Heredity is also known to determine hair loss problems.

Discussed here are some of the other general causes of hair loss commonly seen:

Poor Nutrition: This is one of the commonest reasons for hair loss, especially in India. Iron deficiency (anemia) tops the list and is followed by protein deficiency. Improper absorption of the nutrients can also lead to poor nutrition.

Crash dieting: Excessive dieting especially mono dieting, which involves completely avoiding a particular type of food group, causes a disturbance in the balance of protein, carbohydrates and fat, leading to hair loss, which sometimes does not             reverse even after the patient gets back to a normal diet.

Oral contraceptives: Certain oral contraceptives using synthetic progesterone can lead to female pattern baldness. Then again, stopping oral contraceptives is also known to be associated with generalized hair loss for sometime.

Poor circulation: A study of young men diagnosed with male pattern baldness showed that the blood flow to their scalps was on average 2.6 times lower than in a control group. Follicles that are constantly deprived of blood, and therefore             nutrients, cannot produce hair properly.

Smoking: Nicotine (tobacco) negatively influences the micro-circulation of the scalp leading to increased hair loss.

Mental stress: There is increased hair loss when an individual is highly stressed - the exact mechanism of this is not known.

Dandruff: This is inflamed flaky skin on the scalp and it hinders proper circulation and nutrition to the hair thereby causing increased hair loss.

Medications: Drugs used in the treatment of gout, depression, arthritis, high blood pressure and heart problems can lead to increased hair loss. Chemotherapy drugs, radiation treatment are other common causes.

Presence of other systemic illnesses such as Diabetes, Lupus, Scleroderma

Hormonal changes: Pregnancy, childbirth, menopause, hypothyroidism, hyperthyroidism, etc. can lead to significant hair loss.

Hair treatments: Chemical treatment of hair especially with ammonia based products, perming, straightening, ironing, etc can lead to loss of hair

Infection of the scalp - especially ringworm of the scalp can lead to hair loss.

Local diseases of the scalp such as Psoriasis, lichen planus, etc.

While recuperating from a serious illness such as high fever, sudden or excessive weight loss, after a surgery or from metabolic disturbances