Types of Hair Loss

What is hair?

In the outer layer of skin, there are hair follicles that produce fine outgrowths (hairs) out of a protein (keratin). Hair follicles make new hair cells while the old, then dead, cells are being pushed out at the velocity of 15 centimeters per year. In fact, the visible hair is a string of those dead cells. The growing phase of hair is called anagen which lasts 2 to 3 years, followed by a resting phase called telogen, which lasts for about 4 months. Typically, in its fourth year, the hair falls out and is replaced within 6 months by a new one. Every adult has about 100,000 to 150,000 hairs on the scalp and loses up to a hundred of them daily. There are different types of hair in your body such as scalp hair, eyebrows, and eyelashes.

What is hair loss?

Alopecia or as it is commonly called hair loss is a prevalent bodily condition that has always been a matter of concern for most individuals. Alopecia can be caused by a number of factors from environmental elements to medical conditions and genetics; Hence, making the diagnosis complicated in some cases. The most common alopecias are androgenetic alopecia, telogen effluvium, alopecia areata, ringworm, scarring alopecia, and baldness due to cosmetic over-processing. Alopecia cases are categorized as follows:

Androgenetic alopecia

Androgenetic alopecia or as it is commonly called “male pattern baldness” is responsible for more than 95% of hair losses in males. Studies show that nearly 70% of the men aged 35 are suffering from hair loss. The number goes up to 85% in fifty-year-old men. Undoubtedly, hair loss has serious consequences in everyone’s life and the affected seeks professional help to resolve the problem. In MPB cases, one inherits hair follicles with a sensitivity to dihydrotestosterone (a byproduct of testosterone or male hormone). These follicles begin weakening and finally will fall off. Receding hairline and thinning crown especially in temples and mid-anterior scalp are the evident features of MPB. This pattern develops throughout the entire top of the scalp, leaving only a rim pattern of hair remaining. Sometimes, even this remaining rim of hair can be affected.

Women hair loss

More than 40% of hair loss cases belong to the women, which have crushing effects on many of them. Although, about 90 percent of all cases in men are caused by hereditary MPB, hair loss can be triggered by a multitude of conditions in women. In androgenetic alopecia, due to the action of male hormones, the majority of women have scattered thinning on all areas of the scalp in comparison with the men, who have more distinct patterns of baldness. Contraceptives may cause hair loss in women. During pregnancy, there is an increase in hair loss likewise in menopause.

Effluviums (defluviums)

Effluviums are hair loss conditions which happen during various phases of hair growth. They consist of the following:

Telogen effluvium: This is the second most prevalent form of hair loss. Telogen effluvium (TE) appears as a scattered thinning of hair on the scalp, which may not be even all over. Typically, the top of the scalp is affected more than the sides and back of the scalp with commonly, no hairline recession. Individuals with this condition never lose all their hair on the scalp. Typically, in TE, the hair follicles are in a resting state and the condition is completely reversible. The causes are so varied including intensive dieting, the time shortly after giving birth in women, vaccinations, diet deficiency, exposure to toxins, physical impacts, chronic stress, using drugs such as antidepressants, thyroid hormone problems.

Anagen effluvium: This hair loss condition is similar to TE, but progresses more rapidly. Moreover, it can contribute to a complete hair loss. It is seen in patients undergone cancer treatments (using cytotoxic medications). Also, toxins may cause anagen effluvium (AE). In AE, the follicles are frozen in time and the recovery is quite rapid once the cause is removed.

Alopecia areata

This is the third most common form of baldness. Statistics show that 2% of the population will get alopecia areata (AA) at some point in their lifetimes. AA is a non-contagious disease in which the immune system attacks hair follicles. The reason is still unknown. It can affect just one or two small areas or cover the entire scalp and even the entire body. Genes, viruses, hormones, allergies, and toxins may contribute to the AA. The follicles can re-grow if the systemic condition diminishes. In 70% of cases, the problem resolves completely.

Scarring alopecia

There are different sorts of scarring hair loss (also known as cicatricial alopecia). The main feature is the replacement of the irreversibly destructed hair follicles by scar tissues. It appears as small patches that grow with time. There may be some inflammation, itching, burning, or pain in the areas.

Congenital hypotrichosis: In this permanent state, there has never been any hair growth in the area. The causes include genetic disorders and defects of embryonic development.
Infectious agents: Ringworm is a contagious fungal infection that affects the skin and causes areas of hair loss. It can be passed by skin-to-skin contact, combs, pool surfaces, unwashed clothing, etc. Folliculitis is the inflammation of hair follicles divided to non-infectious cases (caused by oils and greases applied to the skin) and infectious cases (due to bacterial infections). In severe conditions, the hair follicles are permanently destroyed. Piedra is another fungal infection that weakens the hair fiber. Demodex folliculorum, seborrheic dermatitis are other infectious conditions that contribute to hair loss.

Hair shaft defects

Alopecia resulting from physical hair defects are infrequent compared to the other causes of baldness. The most common ones are as follows:

Loose anagen syndrome: In this state, the hair is loose and easily pulled out. The cause is unknown.

Traction alopecia and trichotillomania: Anything that pulls on the roots of the hair such as a tight pony tail can damage the follicles permanently. Trichotillomania is a condition in which the individuals pluck out their own hair.

Monilethrix: In this condition there are nodes and constrictions along the length of a hair.

Overprocessing, cuticle stripping, and bubble hair: Bleaching, dyeing, and other hair processing procedures use chemicals that can be harmful to the hair follicles. Too Repetitious cosmetic approaches can contribute to permanent damage to the hair follicles.

Trichorrhexis nodosa: This is a focal defect in the hair fiber in the absence of cuticle due to too much brushing, manipulating, processing, etc.

Drug Induced Hair Loss

Using some drugs can result in temporary or permanent hair loss. Everyone has to check the drug’s brochure in this regard. Some of the drugs that can cause hair loss are as follows:

• Cytotoxic drugs used in chemotherapy and radiation for cancer treatment
• All drugs derived from vitamin A
• Anticoagulants
• Cholesterol-lowering drugs
• Anticonvulsants
• Antidepressants
• Antifungals
• Amphetamines
• Beta-blocker drugs
• Hormones
• Anti-inflammatory drugs
• Drugs used to treat the thyroid
• Drugs used to treat indigestion
• Drugs used to treat Parkinson’s disease