Hair loss

Hair loss, also known as alopecia or baldness, is the loss of hair from parts of the head or the body. This condition can range from losing hair in tiny patches to losing hair across the entire body. While hair loss is a common experience, it does not always involve inflammation or scarring. For many, hair is a major part of their identity and self-image. Men often associate a full head of hair with youth and vigor. Women may view hair as a symbol of femininity and attractiveness. Because of these connections, hair loss can lead to psychological distress.

To understand hair loss, one must understand the hair growth cycle. Hair grows in specific stages. The first is the anagen phase, which is a long growing phase. This is followed by a short resting phase called the telogen phase. In a condition called telogen effluvium, a large number of hairs enter the telogen phase at the same time. This results in sudden shedding and thinning. This often happens after major physical or psychological stress. Examples include childbirth, major surgery, or poisoning.

There are several distinct types of pattern hair loss. Male-pattern hair loss is caused by a combination of genetics and male hormones, specifically dihydrotestosterone. This usually begins at the temples and the crown. Female-pattern hair loss also occurs, but the exact cause remains unclear. In women, this thinning typically happens at the frontal and parietal areas of the scalp. Another type is alopecia areata, which is an autoimmune disorder. In this condition, the body's immune system attacks the hair follicles. This can cause hair to fall out in circular patches.

Other causes of hair loss involve external factors or specific medical conditions. Traction alopecia is caused by pulling hair with excessive force, such as through tight ponytails or cornrows. Frictional alopecia occurs from the constant rubbing of hair or follicles. Some people also experience trichotillomania, which is the compulsive pulling of hair. Medical treatments can also be a major factor. For example, chemotherapy targets rapidly dividing cells. This can cause almost 90% of hair to fall out shortly after treatment begins.

Infections and skin diseases can also trigger hair loss. Fungal infections, such as tinea capitis, can cause hair to fall out. Microscopic mites called Demodex folliculorum can also cause thinning. These mites live in oily scalp environments and feed on sebum. This process denies the hair essential nutrients. Other conditions like lupus erythematosus or sarcoidosis cause hair loss accompanied by inflammation or scarring. Even certain hormonal imbalances, such as hypothyroidism, can lead to frontal hair thinning.

Statistics show how widespread these conditions are. By age 50, pattern hair loss affects about half of all men. It also affects about a quarter of all women. Approximately 2% of the population will develop alopecia areata at some point. A healthy head typically has between 100,000 and 150,000 hairs. On average, a person loses about 100 strands of hair every day. To maintain normal hair volume, the body must replace hair at the same rate it is lost.

Managing hair loss involves various medical and personal approaches. For pattern hair loss, people may use medications like minoxidil or finasteride. Some individuals choose hair transplant surgery to restore hair. For alopecia areata, doctors may use steroid injections in the affected areas. However, these injections often need to be repeated to stay effective. Some people find relief through acceptance or by shaving their heads. Understanding the specific cause is the first step in determining the best way to handle the condition.