Many factors affect hair growth. Malnutrition, disease and hormone imbalance may inhibit the normal
growing pattern the taking of steroid drugs will promote hair growth on the body, and may slow that on
the scalp. Any abnormal shedding of hair should be checked by a doctor.
Some people believe mistakenly that frequent cutting will increase hair growth. They are wrong. Hair is
not like the shoots of a plant or tree, which may respond in this way. The hair you see is dead, and
nothing can increase its vigour.
The failure of some people to grow their hair as long as they would wish is more likely to be due to
heredity than to disease or drugs. You genes decide most things about your body, including hair growth.
People whose hair has a short growing cycle – say two years instead of six – can never grow longer than
30cm (2in). Then it will fall out, and the follicles will rest for a time before sprouting new hair.