Grey hair is a familiar sign of ageing but at times graying starts at young age. The age when greying starts depends on your genetic inheritance. Loss of hair color before the age of 35 is termed premature greying. In Ayurveda this is called Palitya. Persons with pitta type of constitution are prone to be affected by this ailment. A white hair is produced by the formation of numerous air spaces throughout the cells composing it.

Loss of hair color is due to a gradual decline in the production of a pigment-melanin the Bhrajaka Pitta in Ayurveda terminology , in the hair bulb. White hair has no pigment, and gray hair has some but not as much as a red, black or brown hair. Not all hairs respond in the same way or at the same time. So the graying process usually is gradual. The first grey hair usually appears near the temples the region of Shankha marma . Then the greyness spreads to the crown, and later to the back of the head.

RAPID GRAYING:
A black colour or the natural darkness of the hair cannot of itself suddenly turn white. Hairs grow for years with pigment inside them, and since they are 'dead' there is no process by which the melanin throughout a hair can be naturally destroyed rapidly (although it may be bleached by sunlight over many years). Apparent rapid greying may be due to a selective shedding of pigmented hair in a person who has some gray hairs, which are retained. Shedding of this kind usually takes several months, but can happen within a few days.

CAUSES OF GREYING :

1. Stress and tension, Excessive passion, anger and psychic strain.which tightens the scalp and reduces circulation-Pitta aggravating life style.
2. Poor diet and imbalanced diet like - Excessive intake of tea, coffee,
alcohol, meat, and fried, oily, greasy, spicy, sour, and acidic foods -
Pitta aggravating diet.
3. Hormonal changes due to pregnancy or menopause.
4. Strong Medication for acute disease prolonged medication for chronic
disease.
5. Illness and/or allergies sinusitis (peenas) and allergic rhinitis
6. Over-use of dyes
7. Genetic tendencies

Ayurveda further explains that in order to get thick glossy hair, one must ensure the roots are firm and the scalp healthy. Just as drought and blazing heat destroys a lawn, heat is detrimental to hair. Too much sun can dry the hair and weaken the scalp and hair roots.

Sometimes hair loss results from "high heat" within the body, which can also damage hair roots. Excessive intake of tea, coffee, alcohol, meat, and fried, oily, greasy, spicy, sour, and acidic foods disturbs Pitta in the body and can reduce the moisture and nutrients reaching the hair follicles and may lead to premature greying.Thus it is better to keep the brain and scalp cool, so even when washing hair, use cold or lukewarm water. Cold water is more efficient in removing soap, and helps to tone the scalp and refresh the nervous
system.