A careful medical history and examination of the hair and scalp are usually enough to diagnose the nature of your hair loss.
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.
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.

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.
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.
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.
