Alopecia (Hair Loss)

Alopecia or hair loss can have many forms and causes. It affects both sexes and all age groups. Alopecia does not refer to one specific hair loss disease - any form of hair loss is alopecia. Hair loss can be caused by a number of conditions. Some diagnoses have alopecia in their title, such as alopecia areata or androgenetic alopecia, but many do not, such as telogen effluvium.

Telogen Effluvium

Telogen effluvium is characterized by sudden, diffuse hair loss caused by an interruption in the normal hair growth cycle. This interruption is often caused by trauma, such as a car accident, severe stress or illness, chemotherapy, pregnancy, major surgery, etc. This trauma causes large numbers of hair follicles that are in the growth phase to suddenly enter the resting (telogen) phase. Some of the aforementioned causes of telogen effluvium are temporary and hair growth recovers after about three months. Although telogen effluvium is the second most common form of hair loss (androgenetic alopecia is the first), it is a poorly defined condition as very little research has been done to understand it.

Anagen Effluvium

Anagen effluvium is a diffuse hair loss like telogen effluvium but it develops much more quickly and individuals can lose all their hair. Anagen effluvium is a common side effect of cancer medications but few studies have examined its clinical characteristics. It is a type of hair loss that is characterized by hair breakage rather than hair loss. This hair loss is reversible once the cancer treatment course is stopped.

Alopecia Areata

Alopecia areata is a condition that is characterized by patchy hair loss over the scalp. It is an autoimmune disease in which the person's immune system attacks its own body, in this case, its hair follicles. Two percent of the population will develop alopecia areata at some point in their lives. This type of alopecia is sometimes attributed to heredity but some other factors might be involved. Alopecia areata is an unpredictable disease. In some people, hair grows back but falls out again later. In others, hair grows back and remains. Each case is unique. Because it causes bald spots on the head, especially in the first stages, it is sometimes called spot baldness. In about one percent of cases, the condition can spread to the entire scalp (alopecia totalis) or to the entire epidermis (alopecia universalis).

Androgenetic Alopecia

Norwood scale

Androgenetic alopecia (alopecia androgenetica) or hereditary baldness is the most common form of hair loss, affecting both men and women. As its name indicates it is coded in our genes. In men it is known as male pattern baldness. Having a bald father alone does not automatically imply that you will become bold too. But if your father and both of your grandfathers are/were bold then the chances of you suffering from male pattern baldness are very high. In some cultures it is believed that male pattern baldness is inherited from the mother’s side of the family but this theory has not been confirmed. Androgenetic alopecia in women is called female pattern baldness. The difference between the male and female form of baldness is in its location and pattern. The male form affects the top of the scalp and the frontal area whereas the female form is often a diffuse hair loss affecting the whole scalp. The extent and pattern of male pattern baldness is generally classified on the Hamilton-Norwood scale, as pictured above, whereas the Ludwig classification is used to define the extent of female pattern baldness. But baldness is not actually hair loss. Hair is not lost, but instead it becomes miniaturised and very fine, colourless and reverting to peach fuzz (vellus hair).