How fast does hair grow
The rate of hair growth varies considerably but on average it is one centimeter per month. The growth is greater in summer than in winter. It is maximum in the ages between 15 and 30 years. Cutting or shaving does not make hair grow faster. Neither does trimming effect the growth rate in any way (though trimming does make your hair look good by eliminating the straggly ends).
Each hair undergoes cyclic activity in three-phase: the growth phase or anagen last 3-4 years; following anagen is a short period of transition or catagen, following which is the phase of telogen or resting phases (2-3 months) the hair becomes detached from its root and falls out, as a new growing hair replaces it in the follicle.
At a given time, 10-15% of the scalp hair is in an inactive phase, ready to fall out, while the remaining are in various stages of growth. A loss of up to 100 hairs per day is normal and is something you should not worry about as most of the lost hair would be replaced. With age, however, the rate of replacement slows down; so as you grow older, there is a natural tendency of some amount of sparseness of your scalp hair
What controls the hair growth
01. Family background
Hair, like any other aspect of your looks, is best improved by testing your system well. A good balanced diet is what is really required. An inadequate diet disturbs the structure, the growth and the color of hair. When there is a total deficiency of protein, the hair becomes spares, fine, brittle, dry, and light-colored. The severe hair loss seen after crash diets is primarily due to protein deficiency. High protein diets, especially those containing gelatin and cysteine, increase the rate of hair growth. Deficiency of pantothenic acid leads to premature graying of hair in animals. Lack of essential fatty acids also caused hair to fall. Iron deficiency, especially in women, has been associated with hair loss, while iron supplementation hastens the growth of hair. Zinc deficiency also leads to hair fall. So an ideal diet for hair growth should contain adequate amounts of iron, zinc, protein and fatty acids.
With increasing age, there is a decrease in hair growth. The replacement of shed hair is also incomplete and this results in sparsity of hair. In men there is a recession of the hairline and sometimes definite areas of baldness on the male sex hormones – the andorgens. Rarely this hormone-mediated baldness is seen in women too.
A number of other hormonal disorders can cause hair loss – thyroid disorders being commonest. Though during pregnancy, hair loss slows down or may even stop altogether, excessive hair fall commonly occurs three to four months after delivery. Contraceptive pills also cause excessive hair loss and this stops when the pill is discontinued.
Any severe illness, be it physical illness (surgery, accident, fever, etc.) or even mental stress, can result in hair loss. However, this hair loss is reversible and recovers in about 3-6 months.