Categories of Hair Loss

The term alopecia means partial or complete loss of hair, and occurs in both men and women. Thinning hair is a common occurrence with aging. Not only are we more prone to lose hair as we get older, but the diameter of each strand of hair tends to get smaller and the growth phase shorter with increasing age. ⁽¹⁶⁾

However, there are many other causes for hair thinning other than the natural aging process, which can generally be grouped into five main categories: ⁽²²⁾

• Alopecia areata
• Anagen effluvium
• Androgenic hair loss (male balding and female pattern hair loss)
• Telogen effluvium
• Cicatricial alopecia

Sometimes the types of hair loss blend into each other—especially androgenic hair loss and telogen effluvium. For example, thinning hair can be a symptom of a medical condition (e.g., hypothyroidism), change in physical condition (e.g., after a pregnancy), or change in medication (e.g., stopping birth control pills) which can start out as telogen effluvium but then trigger or unmask androgenic hair loss. ^(29, 30)

If hair thinning or balding is a symptom of another systemic disease, usually these medical conditions can be treated and the hair loss prevented, eliminated, or eventually at least partially reversed as new growth appears. Sometimes hair loss is a side effect of medical treatments and pharmaceutical drugs separate from or in addition to the disease being treated, but is typically not permanent. ⁽²⁹⁾

Hair loss disorders that can cause permanent hair loss can be a result of scarring from trauma (e.g., burns or radiation) or inflammatory medical conditions such as chronic cutaneous lupus erythematosus and follicular mucinosis. Generally referred to as cicatricial alopecia, these conditions can directly or indirectly damage and even destroy hair follicles. ⁽²⁴⁾

And of course, there's heredity, which has been directly linked to two different categories of hair loss—androgenetic alopecia and alopecia areata. Androgenetic alopecia (AGA) is commonly called male baldness and female pattern hair loss, which tends to run in families and is very common. These genes can click on any time after puberty. AGA is also influenced by the androgen hormones in both men and women (e.g., testosterone) and especially the powerful testosterone metabolite, DHT. ^(1, 3, 22)

Alopecia areata is considered a non-scarring hair disorder. It can be patchy or involve losing the entire head of hair. Sometimes it can include the loss of all body hair. ⁽²²⁾

Is Type of Hair Loss Important?

When you are looking in the mirror lamenting the loss of that thick mane of hair you used to have, chances are you really don't care how or why it ended up in your shower drain—but you should, if you want to maximize your chances of treating your hair loss successfully. Diagnosing type of hair loss is important for two important reasons, both of which may help you get your hair back (or at least stop the thinning): ⁽³⁾

• Determine and treat any underlying condition causing the hair loss.
• Appropriately treat your type of hair loss, since treatments can differ in effectiveness depending on category of hair loss and because some drug treatment regimens for hair loss are gender-specific (e.g., anti-androgens combined with birth control pills for women).