Hair Loss Part 1: Types and Causes
Hair is a keratinized structure which grows all over the body with the exception of the palms of the hand and soles of the feet; however some hairs are so fine they are essentially undetectable with the naked eye. Hair follicles, embedded in the skin, are the manufacturing house for hair, and as they produce new hair cells, the dead ones are pushed out of the skin, giving us our beautiful curly, straight, wavy, thick or thin manes.
Each hair follicle has its own life cycle that can be influenced by a variety of factors, including age and overall health. At any point in time, about 90% of the hair on a person's scalp is growing. As a result, the average adult head has about 100,000 to 150,000 hairs and loses up to 100 of them a day. As people age, the rate of hair growth naturally slows down. However one can also suffer from unnaturally slow rates of growth or hair loss, also called alopecia.
There are different types of hair loss:
-Involutional alopecia is the natural hair thinning that occurs with aging. More and more hair follicles become inactive; the remaining hair thus becomes sparse and shorter.
-Androgenic alopecia is a genetically inherited condition that affects both men and women. Commonly known as male pattern baldness in men, it is characterized by a receding hairline and gradual disappearance of hair from the crown and front of the head. Its onset is generally in the early 20’s, but can begin as early as during the teen years. Female pattern baldness, for women, is characterized by thinning over the entire scalp, but more so at the crown. Its onset is not until the 40’s or later.
-Alopecia areata is thought to be a systemic autoimmune disorder in which the body attacks its own hair follicles; it can affect children and young adults. This results in patches of baldness appearing suddenly on the scalp. It can progressively spread to the entire head (alopecia totalis) or even to the entire skin (alopecia universalis). However in 90% of cases, the hair returns within a few years.
-Alopecia universalis, sometimes a development of alopecia areata, is characterized by hair loss over the entire body, including eyebrows, eyelashes, and pubic hair.
-Trichotillomania, most frequently seen in children, is a psychological disorder thereby a person pulls out their own hair.
-Telogen effluvium is probably the second most common form of hair loss seen by dermatologists. A temporary hair loss, it is characterized by uneven thinning over the scalp. It happens due to a large number of hair follicles entering their resting phase at the same time, causing shedding and the resulting thinning. The condition generally reverses itself once the hair follicles re-enter their active phase.
Hair loss can be linked to many different factors. Some are specific to particular hair loss types, while others are more general.
-Having abnormally high levels of hormones like androgens can cause hair loss. Androgens are hormones that generally enhance male characteristics but are also produced by women in small quantities.
-Genetics can make a person more likely to develop certain hereditary types of hair loss.
-Stress and childbirth can also cause temporary hair loss
-Certain pharmaceutical drugs, such as chemotherapy drugs used in cancer treatment, birth control pills, blood pressure beta-adrenergic blockers, and blood thinners can cause temporary hair loss.
-Burns, injuries, and X-rays can cause temporary hair loss at the affected spot. The hair generally grows back after healing.
-Certain systemic autoimmune diseases may cause the body to attack its own hair follicles, leading to alopecia areata.
-Cosmetic hair treatments, such as shampooing too frequently, perms, bleaching, and dyeing can make the hair brittle and weak, leading to overall thinning. Likewise, certain hair styling practices can really damage the hair, like tight braids, the excessive use of rollers or hot curlers, or running hair picks through tight curls. Although these practices do not cause baldness and the damage they cause can be easily reversed, severe damage to the hair or scalp can occasionally cause permanent bald patches.
- Certain medical conditions, likediabetes,Thyroid disease, anemia, iron deficiency, and lupus can cause hair loss until the underlying cause is treated.
-A low-protein or extremely calorie-restricted diet can also cause temporary hair loss.
So as we can see, some hair loss problems can be easily remedied; others take care of themselves with time; others cannot be completely stopped. In our next article, we will look at common hair loss treatment methods.