There are numerous ways to categorize hair loss. One must first examine the scalp to determine if the hair loss is due to the physical destruction and loss of hair follicles. If the scalp appears perfectly normal with plenty of empty hair follicles, this is called non-scarring hair loss. On the other hand, the follicles are permanently destroyed in scarring hair loss. Localized, small areas, large areas, or the whole scalp may be affected in scarring and non-scarring hair loss. Non-scarring hair loss can also be seen in situations where there is physical or chemical damage to the hair shaft resulting in breakage. Occasionally, it may be necessary to do a biopsy of the scalp to distinguish these conditions. Sometimes, a physician may pull a hair to examine the appearance of the hair shaft as well as the percentage of growing hairs (anagen phase). This article will concentrate on the non-scarring types of hair loss.

Some conditions produce small areas of hair loss, while others affect large areas of the scalp. Common causes of patchy hair loss are

• alopecia areata (small circular or coin size patches of scalp baldness that usually grow back within months)
• traction alopecia (thinning from tight braids or ponytails)
• trichotillomania (the habit of twisting or pulling hair out)
• tinea capitis (fungal infection)

A common condition, alopecia areata usually starts as a single quarter-sized circle of perfectly smooth baldness. These patches usually regrow in three to six months without treatment. Sometimes, white hair temporarily regrows and then becomes dark. The most extensive form is called alopecia totalis, in which the entire scalp goes bald. It’s important to emphasize that patients who have localized hair loss generally don’t go on to lose hair all over the scalp. Alopecia areata can affect hair on other parts of the body, too (for example, the beard or eyebrows).

Alopecia areata is an autoimmune condition in which the body attacks its own hair follicles. Most patients, however, do not have systemic problems and need no medical tests. While alopecia areata is frequently blamed on “stress,” in fact, it may be the other way around; that is, having alopecia may cause stress.

Treatments for alopecia areata include injecting small amounts of steroids like triamcinolone into affected patches to stimulate hair growth. Although localized injections may not be practical for large areas, often this is a very effective treatment in helping the hairs return sooner. Other treatments, such as oral steroids, other immunosuppressives, or ultraviolet light therapy, are available for more widespread or severe cases but may be impractical for most patients because of potential side effects or risks. In most mild cases, patients can easily cover up or comb over the affected areas. In more severe and chronic cases, some patients wear hairpieces; nowadays, some men shave their whole scalp now that this look has become fashionable.