Hair Loss Causes NYC - (212) 644-9494 - New York, NY
Causes
Most people normally shed 50 to 100 hairs a day. But with about 100,000 hairs in the scalp, this amount of hair loss shouldn't cause noticeable thinning of the scalp hair.Due to hormonal changes, irritation or damage, some hair follicles have a shorter growth phase and produce thinner, shorter hair shafts. Your hair goes through a cycle of growth and rest. The course of each cycle varies by individual. But in general, the growth phase of scalp hair, known as anagen, typically lasts two to three years. During this time, your hair grows just less than 1/2 inch (1 centimeter) a month. The resting phase is called telogen. This phase typically lasts three to four months. At the end of the resting phase, the hair strand falls out and a new one begins to grow in its place. Once a hair is shed, the growth stage begins again.
Gradual thinning is a normal part of aging. However, hair loss may lead to baldness when the rate of shedding exceeds the rate of regrowth, when new hair is thinner than the hair shed or when hair comes out in patches.
Causes of specific types of hair loss
Pattern baldness (androgenetic alopecia). In male- and female-pattern baldness, the time of growth shortens, and the hairs are not as thick or sturdy. With each growth cycle, the hairs become rooted more superficially and more easily fall out. Heredity likely plays a key role. A history of androgenetic alopecia on either side of your family increases your risk of balding. Heredity also affects the age at which you begin to lose hair and the developmental speed, pattern and extent of your baldness.
Cicatricial (scarring) alopecia. This type of permanent hair loss occurs when inflammation damages and scars the hair follicle. This prevents new hair from growing. This condition can be seen in several skin conditions, including lupus erythematosus or lichen planus. It's not known what triggers or causes this inflammation.
Alopecia areata. This is classified as an autoimmune disease, but the cause is unknown. People who develop alopecia areata are generally in good health. A few people may have other autoimmune disorders, including thyroid disease. Some scientists believe that some people are genetically predisposed to develop alopecia areata and that a trigger, such as a virus or something else in the environment, sets off the condition. A family history of alopecia areata makes you more likely to develop it. With alopecia areata, your hair generally grows back, but you may lose and regrow your hair a number of times.
Telogen effluvium. This type of hair loss is usually due to a change in your normal hair cycle. It may occur when some type of shock to your system — emotional or physical — causes hair roots to be pushed prematurely into the resting state. The affected growing hairs from these hair roots fall out. In a month or two, the hair follicles become active again and new hair starts to grow. Telogen effluvium may follow emotional distress, such as a death in the family or a physiological stress, such as a high fever, sudden or excessive weight loss, extreme diets, nutritional deficiencies, surgery, or metabolic disturbances. Hair typically grows back once the condition that caused it corrects itself, but it usually take months.
Traction alopecia. Excessive hairstyling or hairstyles that pull your hair too tightly cause traction alopecia. If the pulling is stopped before there's scarring of your scalp and permanent damage to the root, hair usually grows back normally.