Typical male pattern baldness involves a receding hairline and thinning around the crown with eventual bald spots. Ultimately, you may have only a horseshoe ring of hair around the sides. In addition to genes, male-pattern baldness seems to require the presence of the male hormone testosterone. Men who do not produce testosterone (because of genetic abnormalities or castration) do not develop this pattern of baldness.
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 right vitamins and minerals play a major role in keeping your hair healthy. Any nutritional deficiencies can lead to thinning hair or even total baldness. It is a well known fact that an under active thyroid can result in frizzy or brittle hair while an overactive thyroid turn hair greasy and limp.

Both men and women tend to lose hair thickness and amount as they age. Inherited or "pattern baldness" affects many more men than women. About 25% of men begin to bald by the time they are 30 years old, and about two-thirds are either bald or have a balding pattern by age 60.
Hair loss from menopause or childbirth often returns to normal 6 months to 2 years later
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.
