Before recommending or performing a hair restoration procedure, a hair restoration doctor will conduct a scalp examination to perform a hair loss diagnosis. If the examination indicates that hair loss may be due to a condition other than male or female pattern baldness, the physician will seek the cause with other diagnostic measures. In some cases an underlying condition may have to be treated before hair restoration is undertaken.
A hair pull is a diagnostic procedure used in virtually every patient with a complaint of unexplained hair loss, to assess the presence or absence of any abnormalities in the hair growth cycle. About 25 to 50 hairs are removed from the scalp by a series of gentle hair pulls. Normally only a few hairs are dislodged with each pull. When more are removed the possibility of an abnormality of hair growth cycling is indicated; the ends of the pulled-out hairs may be examined under a microscope to evaluate the condition of the hair shaft and the bulb (the end of the hair shaft extracted from the hair follicle).
Variations of the hair pull are the phototrichogram and hair window:
Phototrichogram— hairs are clipped or shaved in an area of the scalp and consecutive photographs taken over a period of 3 to 5 days to determine the pattern of hair growth.
Hair window— hairs are clipped or shaved in an area of the scalp and hair growth is evaluated over the next 3 to 30 days.
Abnormalities of hair growth cycling is a relatively uncommon cause of hair loss but may occur at any age. Underlying causes of these abnormalities include thyroid hormone imbalance, nutritional deficiencies, side effects of certain drugs, anemia and other systemic illness, and psychological stress.
A biopsy of the scalp is usually performed only if additional information is needed to evaluate the mechanism of hair loss inside the hair follicle. Biopsy is not necessary in the great majority of patients evaluated for hair loss and hair restoration.
Hair Shaft Evaluation
If a hair shaft abnormality or infection is suspected, the hair shafts removed from the scalp by hair pull are examined under a microscope. Hair shaft abnormalities and fungal, bacterial or viral infection can be responsible for hair loss associated with hair breakage, hair shedding and hair that is unruly.
Hair analysis is a laboratory test performed if a hair shaft abnormality needs to be assessed for (1) altered hair-protein profile due to an inherited abnormality, or (2) drug ingestion or heavy metal contamination. Hair analysis is ordered by a hair specialist physician only to determine the cause and mechanism of a hair shaft abnormality. The test has no value for the diagnosis of systemic disease or nutritional status, contrary to claims by non-physician “hair analysis specialists”.
Fortunately, most persons seeking hair restoration in the U.S. are among the 80 million men and women who have male and female pattern hair loss, a condition simple to diagnose and easy to treat. Extensive diagnostic work-ups for these easily recognized conditions are usually not necessary. There are other causes of hair loss, however, and it is essential that the cause of hair loss be evaluated before hair restoration is undertaken.