There are a number of causes of hair loss in women, and in most cases, several etiologies are working together. In some situations, the hair loss is temporary, but when heredity is involved, the hair loss is almost always progressive and sometimes irreversible. Female pattern hair loss accounts for more than 95% of all cases of hair loss in women (and more than 99% in men), and is genetically determined. Aging, along with the associated hormonal changes that women undergo, accelerate this process, accounting for the higher incidence of hair thinning especially in post-menopausal women.
What follows is a summary of some of the most important causes of hair loss
Female pattern hair loss- also called androgenetic alopecia, is estimated to manifest itself in more than 30% of all women. This is a progressive process, and usually underlines many cases of hair loss contributed to by other etiologies. No specific genetic path has been proven, but in most cases, the individual has one or more female relatives (e.g. mother, aunt, grandmother) with hair thinning as well. Several patterns have been described with female pattern hair loss, but is most commonly characterized as diffuse thinning concentrated along the top of the scalp, sometimes sparing the very frontal hairline. Oftentimes, the sides and back of the scalp can also be affected. The process usually begins in the late 30s, early 40s, but can appear at any time (Click here to see examples of these cases treated with hair transplantation).
Hormonal changes- for most women, menopause is associated with many physical, as well as emotional changes. One area affected is the scalp, where the change in the ratio of estrogen to testosterone results in an acceleration or onset of female pattern thinning. Pregnancy is another example of fluctuations in hormones leading to hair loss, which most commonly starts several weeks to months after delivery, and which is contributed to by the physical stress it takes on the body. During pregnancy, what typically happens is that, due to the increased rate of metabolism and the higher level of certain hormones, the body holds onto more of its hairs, losing far less than the normal amount of 100 hairs a day. After delivery, once the pregnancy is over, the body then typically sheds all of the hair it would have shed during the pregnancy, therefore losing much more than 100 hairs a day. This results in a mild to moderate thinning that many women notice. Many other hormonal imbalances, most quite rare (other than low thyroid levels), can be associated with hair loss. Besides the relatively common hypothyroidism, which is effectively treated with thyroid hormone replacement which usually works to also slow down the hair loss process, another potential hormonal imbalances is elevated testosterone levels which can be seen with polycystic ovaries.
Stress- for most people, stress is considered to be something psychological, but a variety of processes inflict physical stress on our bodies. A very high fever, significant weight loss associated with dieting, pregnancy, and surgery are some of the causes of stress-induced hair loss, and almost always are temporary, with the hair loss usually starting six to 12 weeks after the episode and regrowth occurring after another two to three months. But emotional stress, such as grieving or depression, can play a roll in hair loss as well.
Trauma- which can include a number of different processes. Besides the obvious incidents that can result in scarring, such as burns and accidents, hair can be damaged by the wearing of hair weaves and even hair styles that chronically pull on the existing hairs. This pulling process that results in hair loss is so common that there even is a name for it- traction alopecia. For African American women, this is one of the most common causes of hair thinning, but can occur in any woman and is sometimes reversible. In all of these cases of scarring, it is indeed possible, with proper transplant techniques, to get hair to grow, thus concealing the scarring (Click here to see examples).
Trichotillomania- an obsessive compulsive disorder where the individual repeatedly unconsciously pulls out hair. Most commonly occurring in teenage or preteenage girls, with an estimated incidence of 1 to 2% in all females, trichotillomania can result in permanent loss of hair of the eyebrows, eyelashes, and scalp. While certain treatments such as psychological counseling and medications are effective in some cases, the hair loss that can result is usually permanent and thus able to be restored only through transplanting (Click here to see examples).
Prior plastic surgery- such as certain techniques of browlifts and facelifts, is not infrequently associated with incisions that healed with scarring devoid of hair, or distortion of the hairline manifested by such problems as the absence of sideburns or the overly elevated hairline. Similar to other cases of scarring, special transplant techniques can result in hair growth. (Click here to see examples).
Medication and medical treatments- with chemotherapy an obvious example, there are numerous medications that have been reported to be associated with hair loss. Some anti-inflammatories (e.g. Vioxx- which has been taken off the market), antihypertensives such as beta blockers, and birth control and hormone replacement therapy have been associated with hair loss. When choosing an oral contraceptive or hormone replacement medication, it is important to discuss your concerns and goals with your prescribing physician, as these medications can vary in the levels of different hormones they supply. Radiation therapy administered to the head can also result in hair loss, and like with other forms of scarring alopecia, hair transplants can be effective (Click here to see examples).
Local and systemic diseases- includes a wide variety of different medical conditions associated with hair loss. Anemia (low levels of iron or of ferritin, the protein that carries iron in the blood), nutritional abnormalities, some autoimmune diseases such as lupus and rheumatoid arthritis infections, and hypothyroidism, to name the most common. In many of these cases, the patient has an underlying genetic risk for hair loss, and the active process accelerates this hair loss. Attempts to determine the disease are undertaken to slow down or even stop the progression of the hair loss, but usually does not result in any significant degree of hair regrowth.
Nutritional factors- certain diets, especially when they involve crash dieting, or some chronic conditions like alcoholism, may result in hair loss. For healthy hair growth, it is known that some elements, such as iron and zinc, as well as an adequate level of protein amino acids, are required. For women who maintain a complete diet, this should not be an issue, but there is little harm in taking supplemental iron and zinc, as well as other nutritional items associated with healthy hair growth.
For healthy hair growth, it is known that some elements, such as iron and zinc, as well as an adequate level of amino acids (provided through protein) are beneficial and required. For women who maintain a complete diet, this should not be an issue, but there is little harm, and in fact it is recommend by Dr. Epstein, that patients take supplemental amounts of these elements, as well as other nutritional items such as biotin.