Patient education: Female pattern hair loss and male pattern hair loss (androgenetic alopecia) (Beyond the Basics)

OVERVIEW — 

Progressive hair loss is common. The most common types of hair loss are male pattern hair loss (also known as androgenic alopecia in males) and female pattern hair loss (also known as androgenic alopecia in females).

For many people, losing their hair is a frustrating experience. Fortunately, treatments are available that can help to regrow hair or prevent further hair loss.

CAUSES — 

The hair follicle is a structure that encases the lower part of the hair shaft (the shaft is the part you can see outside your scalp). Each follicle contains blood vessels and nerves in the lower part of the hair follicle. All hair follicles are present at birth; throughout a person's lifetime, each follicle grows and sheds single hairs in a repetitive cycle. The growth phase for a single new hair lasts two to three years. At the end of this time, growth ceases and the follicle enters a resting phase. After three to four months in the resting phase, the hair is shed and the next growth cycle begins.

On a normal scalp, approximately 80 to 90 percent of follicles are growing at any time. Each day, about 75 follicles shed their hair while the same number enter a new growth phase. In people with male pattern hair loss, hormones related to testosterone (also called androgens) cause hair follicles to have a shorter-than-normal growth phase, resulting in hair shafts that are abnormally short and thin. These follicles are said to be "miniaturized." This also happens in people with female pattern hair loss, although it's less well understood exactly what factors contribute to this process.

Genetics — It is not fully understood why some people develop male pattern hair loss and others do not. It is generally accepted that there is a genetic component, but the exact way in which family history affects a person's chance of developing male pattern hair loss has not been determined.

Genetics also appear to play a role in the risk for female pattern hair loss, although other factors, such as normal aging or changes in hormone levels, may also be important. As an example, abnormal levels of androgens, such as testosterone or dihydrotestosterone, in the blood are the cause of hair loss in a minority of females. Additional research is necessary to provide a better understanding of the role of genetics and other factors.

SYMPTOMS — 

Male pattern hair loss is characterized by gradual hair thinning that most often affects the crown and frontal areas of the scalp (figure 1).

Female pattern hair loss usually affects the crown and frontal areas of the scalp. In many females, the frontal hair line is preserved. Typically, the hair loss is more diffuse than in male pattern hair loss; people with female pattern hair loss rarely develop completely bald areas (figure 1).

DIAGNOSIS — 

Female pattern hair loss and male pattern hair loss can usually be diagnosed by examining the scalp. In some cases, you will need blood tests or a biopsy of the scalp to look for other causes of hair loss.

PSYCHOSOCIAL IMPACT OF HAIR LOSS — 

Losing your hair can be frustrating and upsetting. While it's normal and common to lose hair with age, it can still be distressing, especially as people often feel that society reinforces the message that a youthful appearance is more attractive. People with hair loss may struggle with low self-esteem or body image issues.

If you are struggling with the psychosocial impact of losing your hair, speak to a health care provider knowledgeable about the diagnosis and treatment of hair loss. Experienced providers can offer support and may recommend working with a therapist, clinical psychologist, or support group; individual and group therapy can help people adjust and cope with hair loss. Having a supportive partner, family members, or friends can also help.

Some people choose to accept their hair loss and learn to live with it, while others choose treatment (see 'Treatment' below). This is a personal decision.

TREATMENT — 

Several medications are available for the treatment of male pattern hair loss and female pattern hair loss. Surgical options, laser light devices, and injections of platelet-rich plasma may also be considered in some cases.

It usually takes six months or longer to see improvement from treatments.

Some of these treatment options are discussed in more detail below.

Medications

Topical minoxidil — Topical minoxidil (sample brand name: Rogaine) is a medication that you apply directly to your scalp. You can buy it without a prescription. It promotes hair growth by lengthening the growth phase of hair follicles and causing more follicles to produce hair; then, the hairs that are produced tend to be larger and thicker.

How to use — In order to be effective, topical minoxidil must be applied to your scalp, not your hair. Read the package instructions carefully so you know how much to use and how to apply it. Then lightly spread the solution over the affected area with your finger (you do not need to rub it in).

You will need to continue using topical minoxidil for at least six months in order to know if it is working. At first, you might actually notice more shedding of hair; this does not mean the medication is making your hair loss worse. This shedding usually resolves within two months, and by four to eight months, new hair begins to grow. The effects of topical minoxidil usually stabilize after 12 to 18 months of use.

Treatment with topical minoxidil must be continued indefinitely in patients with male or female pattern hair loss. If you stop using it, any hair that has been maintained or regrown as a result of the medication will be lost.

Side effects — Topical minoxidil causes few side effects. Occasionally, the skin on the scalp may become red or irritated, causing itching.

Oral finasteride — Oral finasteride (sample brand name: Propecia) is a prescription medication that comes as a pill. It works by decreasing the production of one of the hormones associated with this type of hair loss, resulting in an increased amount of hair covering more of the scalp. Oral finasteride is most often used for the treatment of male pattern hair loss.

Oral finasteride is used less frequently for the treatment of female pattern hair loss. Finasteride is not safe for use during pregnancy. This is because there is a risk that it could cause abnormal development of the genitalia in a male fetus. People who could be pregnant should not even come into contact with finasteride pills.

Higher doses of oral finasteride (such as those used to treat some prostate conditions) can cause side effects including erectile dysfunction and decreased sex drive in males. However, such side effects are not commonly seen with the 1 mg dose used to treat hair loss in males.

Some studies have suggested that people who take oral finasteride might be at increased risk for suicidality or other psychologic problems like depression or anxiety. It is not clear whether the medication actually causes these problems. However, it's important to be aware of this possibility and tell your health care provider right away if you have symptoms of depression or anxiety. If you are thinking about hurting yourself or someone else, get help right away. In the United States, help is available through the 988 Suicide & Crisis Lifeline. Call or text 988 or go to www.988lifeline.org/chat.

Spironolactone — Spironolactone (brand names: Aldactone, CaroSpir) is a prescription medication that comes as a pill. Like finasteride, it decreases the production of hormones that contribute to hair loss.

People with female pattern hair loss may benefit from treatment with spironolactone. However, spironolactone should not be used during pregnancy, so anyone who could get pregnant must use reliable birth control if they take this medication. (See "Patient education: Birth control; which method is right for me? (Beyond the Basics)".)

Because of its effects on hormones, spironolactone is not used in males.

Potential side effects of spironolactone include headache, dizziness, sleepiness, breast tenderness, and elevated potassium levels in the blood.

Oral minoxidil — Oral minoxidil is a prescription medication that comes as a pill. Oral minoxidil was originally used for the treatment of high blood pressure, but similar to topical minoxidil, oral minoxidil at very low doses may also be helpful for hair growth.

Some of the potential side effects of oral minoxidil are leg swelling and increased hair growth in other areas of the body.

Other medications

Oral dutasteride — Oral dutasteride is an alternative to oral finasteride for the treatment of male pattern hair loss. Like oral finasteride, oral dutasteride works by decreasing the production of one of the hormones associated with androgenetic alopecia.

Topical finasteride — Topical finasteride is a type of finasteride that is applied directly to the scalp. In the United States, topical finasteride is not available as a commercial product.

Surgery — For some patients, surgical treatment of hair loss may be an option. In hair transplantation, healthy follicles from other parts of the scalp are transplanted to areas affected by hair loss.

Products to camouflage hair loss — While they do not treat hair loss directly, there are products that can make thinning hair less obvious. Examples include thickening shampoos, hair dyes, and sprays that make your scalp appear the same color as your hair. Some people also choose to wear a wig, toupee, or headpiece.

Other treatments — Other types of treatment for hair loss include photobiomodulation (also known as low-level laser light therapy) and platelet-rich plasma injections. More research is needed to understand the best way to use these treatments and determine whether there is long-lasting benefit.

Photobiomodulation (low-level laser light therapy) — Combs or other devices that deliver a type of light called "low-level laser light" to the scalp may help to grow hair in some people. These devices are typically used a few times per week.

Platelet-rich plasma — This treatment involves removing plasma from your own blood and injecting it in your scalp. The idea is that growth factors released by platelets, which are involved in wound healing, may stimulate hair growth.

WHERE TO GET MORE INFORMATION — 

Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Hair loss (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Alopecia areata (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Male pattern hair loss (androgenetic alopecia in males): Pathogenesis, clinical features, and diagnosis
Male pattern hair loss (androgenetic alopecia in males): Management
Female pattern hair loss (androgenetic alopecia in females): Pathogenesis, clinical features, and diagnosis
Female pattern hair loss (androgenetic alopecia in females): Management

The following organizations also provide reliable health information.

●National Library of Medicine

(https://medlineplus.gov/hairloss.html, available in Spanish)

●American Hair Loss Council

(www.ahlc.org)

●American Academy of Dermatology

(https://www.aad.org/public/diseases/hair-loss)