Each individual hair survives for an average of 4 1/2 years, during which time it grows about half an inch a month. Usually in its 5th year, the hair falls out and is replaced within 6 months by a new one. Genetic baldness is caused by the body's failure to produce new hairs and not by excessive hair loss
The average person has around 100,000 strands of hair on their head and the average rate of growth is a mere one-half of an inch per month. By the time the ends of your hair actually grow down to your shoulders, they are approximately two years old.
For hair loss due to heredity, age, and hormones, the topical medication Rogaine (minoxidil) can be helpful for both male and female pattern baldness. Expect to wait 6 months before you see results. The oral medication Propecia (finasteride) is effective in some men. This medicine can decrease sex drive. When either medication is stopped, the former baldness pattern returns.

Hair transplants performed by a physician is a surgical approach to transferring growing hair from one part of the head to another. It is somewhat painful and expensive, but usually permanent
For hair loss caused by illness (such as fever), radiation therapy, or medication use, no treatment is necessary. The hair will usually grow back when the illness has ended or the therapy is finished. A wig, hat, or other covering may be desired until the hair grows back.
Call your doctor if:
You are losing hair in an atypical pattern.
You are losing hair rapidly or at an early age (for example, teens or twenties).
You have any pain or itching associated with the hair loss.
The skin on your scalp under the involved area is red, scaly, or otherwise abnormal.
You have acne, facial hair, or menstrual irregularities.
You are a woman and have male pattern baldness.
You have bald spots on your beard or eyebrows.
You have been gaining weight or have muscle weakness, intolerance to cold temperatures, or fatigue.
