Hair Loss in Women

The Causes of Hair Loss in Women

Diffuse Hair Loss

The most common type of hair loss in women occurs in a diffuse pattern. Diffuse hair loss is most often hereditary, but it can also be caused by underlying medical conditions, medications, and other factors.

Common or "hereditary" baldness in women, also called female pattern alopecia, is genetic and can come either the mother’s or father’s side of the family. It is caused by the actions of two enzymes; aromatase (which is found predominantly in women) and 5-a reductase (which is found in both women and men).

The action of 5-a reductase is the main cause of androgenetic alopecia in men, as this enzyme converts the hormone testosterone to DHT. DHT is responsible for the miniaturization (shrinking) and gradual disappearance of affected hair follicles.

Women have half the amount of 5-a reductase compared to men, but have higher levels of the enzyme aromatase, especially at their frontal hairline. Aromatase is responsible for the formation of the female hormones estrone and estradiol. It also decreases the formation of DHT. Its presence in women may help to explain why the presentation of female hair loss is so different than in males, particularly with respect to the preservation of the frontal hairline. It may also explain why women have a poor response to the drug finasteride (Propecia), a medication widely used to treat hair loss in men that works by blocking the formation of DHT.

Women’s hair seems to be particularly sensitive to underlying medical conditions. Since "systemic" problems often cause a diffuse type of hair loss pattern that can be confused with genetic balding, it is important that women with undiagnosed hair loss, be properly evaluated. Medical conditions that produce a diffuse pattern include:

Medical conditions that can cause diffuse hair loss in women
• Obstetric and gynecologic conditions such as post-partum and post-menopausal states or ovarian tumors
• Anemia – iron deficiency
• Thyroid disease
• Connective tissue diseases such as Lupus
• Nutritional - crash diets, bulimia, protein/calorie deficiency, essential fatty acid or zinc deficiency, malabsorbtion, hypervitaminosis A
• Stress – surgical procedures, general anesthesia, and severe emotional problems

A relatively large number of drugs can cause “telogen effluvium,” a condition where hair is shifted into a resting stage and then several months later shed. Fortunately, this shedding is reversible if the medication is stopped, but the reaction can be confused with genetic female hair loss if not properly diagnosed. Chemotherapy causes a diffuse type of hair loss called “anagen effluvium” that can be very extensive, but often reversible when the medication is stopped.

Drugs that can cause diffuse hair loss in women
1. Blood thinners (anti-coagulants), such as warfarin and heparin
2. Seizure medication, most commonly dilantin
3. Medication for gout, colchicines and alopurinol (Xyloprim)
4. Blood pressure medication, particularly the b-blockers (such as Inderal) or diuretics
5. Anti-inflammatory drugs such as prednisone
6. Medications that lower cholesterol and other lipids
7. Mood altering drugs - lithium, tri-cyclics, Elavil, Prozac
8. Chemotherapy
9. Thyroid medications
10. Oral contraceptive agents, particularly those high in progestins
11. Misc. – diet pills, high doses of Vitamin A, street drugs (cocaine)

Localized Hair Loss

Although there are a host of dermatologic conditions that cause hair loss, they produce a pattern that is different from the diffuse pattern of genetic hair loss commonly seen in women and are easily differentiated from it by a dermatologist.

Localized hair loss in women may be sub-divided into scarring and non-scarring types. Alopecia Areata is a genetic, auto-immune disease that typifies the non-scarring type. It manifests with the sudden onset of discrete round patches of hair loss associated with normal skin. It can be treated with local injections of steroids.

Scarring Alopecia can be caused by a variety of medical or dermatologic conditions such as Lupus, Lichen Planus, or local radiation therapy. Hair loss from injuries, or from local medical problems that have been cured, are usually amenable to hair transplantation. Radiotherapy can cause both scarring and non-scarring localized hair loss and it also can be treated with surgical hair restoration if the area is not too large.

Localized female hair loss that occurs around the hairline after face-lift surgery may be permanent. Traction Alopecia, the hair loss that occurs with constant tugging on the follicles, can also be permanent if the habit persists for a long period of time. Both of these conditions can be treated with hair transplantation.

Patterned Hair Loss

Women with this type of hair loss have a pattern similar to what we observe in men. In other words, they have thinning in front or on top of their scalp with preservation of the hair in the permanent zone around the back and sides of the scalp. Thus, the balding is in a characteristic "pattern" rather than generalized. Women with patterned hair loss and a stable donor area may be excellent candidates for surgical restoration.