Harvard Women's Health Watch

Hair thinning? Get to the root of the problem

Hair loss in women can be triggered by multiple causes, and some are treatable.

You look in the mirror and you notice it: your part looks wider than before, and there seems to be more scalp peeking through the strands of hair. While hair loss is often thought of as a man’s problem, at least a third of women will experience thinning hair at some point in their lives.

“There are many different causes of hair loss in women. Some are associated with inflammation in the body. Some are female-pattern hair loss,” says Dr. Deborah Scott, assistant professor of dermatology at Harvard Medical School and co-director of the Hair Loss Clinic at Brigham and Women’s Hospital. Unlike men, women typically experience thinning hair without going bald. In many cases this hair loss can be stabilized with treatment, and it may be reversible. When it’s not, there are a number of new cosmetic approaches that can help.

Understanding hair loss

The first step in dealing with thinning hair is determining what’s happening inside your body that is causing those extra strands to cling to your shoulders and your brush.

Some hair loss is normal. Everyone loses hair as part of the hair’s natural growth cycle, which occurs in three stages:

  1. The anagen stage refers to when a hair strand is actively growing. This stage can last anywhere from two to eight years.
  2. The catagen stage is a short transition phase that lasts up to three weeks. At this point the hair has stopped growing and is preparing to shed.
  3. The telogen stage is the part of the hair cycle when the hair is expelled from the follicle (the structure that produces and holds the hair). After the hair sheds, the follicle then stays dormant, typically for around three months, before a new hair starts to sprout.

Some people may shed a hundred or more strands of hair each day as a result of this natural growth cycle, says Dr. Scott. Normal hair loss is highly individual. “It might be normal for some people to shed 150 hairs a day,” says Dr. Scott. But for someone else that might be extreme. Most people have a sense of how much hair is normal for them to lose. If you suddenly notice more hair than usual falling out, you’re shedding clumps of hair, or your hair seems to be visibly thinning, it may be a sign that something is amiss, says Dr. Scott.

Underlying causes for hair loss

Numerous problems can trigger female hair loss. Some are external, such as taking certain medications, frequently wearing hairstyles that pull the hair too tight, or even a stressful event such as surgery. In other cases, thinning hair is triggered by something going on inside the body—for instance, a thyroid problem, a shift in hormones, a recent pregnancy, or an inflammatory condition. Hair loss may also be genetic.

The most common cause of hair loss in women is a genetic condition known as female-pattern hair loss, or androgenic alopecia. Unlike men with male-pattern baldness, who usually lose hair from the front of the scalp, women might notice a widening of the part at the top of the head. It often begins when a woman is in her 40s or 50s, as new strands of hair grow more slowly. The follicle also changes, and the new hair that grows in is finer and less robust. You might experience this type of hair loss if you inherit certain genes from one or both of your parents, but it may also be spurred on by hormonal shifts that occur during menopause.

Another trigger for hair loss in women is an inflammatory condition affecting the scalp. That might be eczema, psoriasis, or a condition called frontal fibrosing alopecia, which typically causes scarring and hair loss — sometimes permanent — at the front of the scalp above the forehead. This condition seems to be getting more common, but “no one really knows why,” says Dr. Scott. It’s also unclear what causes frontal fibrosing alopecia, but both environmental and genetic factors may be involved.

Other common causes of hair loss include overuse of damaging hair products or tools such as dryers and other devices that heat the hair. Underlying illness, autoimmune conditions such as lupus, nutritional deficiencies, or hormonal imbalances may also cause hair to shed.

Medications to treat hair loss

Treatment for your hair loss will depend on the underlying cause, says Dr. Scott. Sometimes simply addressing a medical condition prompting hair loss will be enough for the hair to regrow. In other instances, a woman might consider a medication or other treatment to replace or regrow lost hair.

Minoxidil (Rogaine), a preparation applied to the scalp, is currently considered the gold standard to treat hair loss. Whether it works depends on the type of hair loss you have. It’s available over the counter, but it produces side effects in some people, including skin irritation or growth of hair in locations where it’s not wanted.

Another medication sometimes used for female hair loss is finasteride (Propecia). This medication is approved only for use in men, but doctors sometimes prescribe it off-label in postmenopausal women. “We don’t have any data that suggest an association between finasteride and female breast cancer; however, we are very careful about using it in anyone who has had breast, uterine, or ovarian cancer. This is largely because there aren’t a lot of long-term data on its use in women,” says Dr. Scott.

Spironolactone (Aldactone) is another medication that your doctor may consider if she or he thinks your hair loss may be hormonally driven.

What to do if your hair is thinning

Awareness that hair loss is a real medical condition has increased significantly, says Dr. Deborah Scott, co-director of the Hair Loss Clinic at Brigham and Women’s Hospital. “I think people now understand that there are treatments available and that they don’t just have to live with it,” she says.

If you notice your hair is thinning, you can take these steps to address the problem:

Get help quickly. If you see an unexpected spike in hair loss, make an appointment with your doctor. Because there are numerous causes of hair loss, figuring out the underlying reason for the problem is essential. The earlier you catch thinning, the more likely it is that it can be stopped or even reversed, says Dr. Scott. “The longer it’s present and the more significant the amount of hair loss, the less likely you are to get back to where you started.” Paying a visit to your general practitioner is a good place to start. She or he can rule out the more obvious conditions that could be causing hair loss, such as thyroid disease. You can also consult a dermatologist or hair loss specialist.

Explore various treatment options. Depending on what’s causing your hair loss, your doctor can recommend treatments most likely to work for you. “Treatments for hair loss are not universally effective,” says Dr. Scott. It’s important to determine the cause of your hair loss so that the treatment can be tailored appropriately.

Address the underlying problem. Even if you seek cosmetic treatments, such as hair transplant procedures, you still need to address the reason your hair is thinning.

Get emotional support. There is a greater understanding today of the emotional toll hair loss can take on women. Be certain to focus not only on your medical needs, but your emotional needs as well.

Other treatments for hair loss

A newer option being used to treat hair loss is platelet-rich plasma (PRP) injections. For this treatment, the doctor draws your blood, divides it into its separate components, recombines the blood fluid (plasma) with a high concentration of platelets (structures in the blood that help with clotting, among other functions), and introduces the resulting preparation back into the scalp. This is done either by directly injecting it into the scalp in the area where hair is thinning or by using microneedling, which involves puncturing the skin with a device to increase absorption. “The science on this isn’t totally worked out. We still don’t completely understand the mechanism behind PRP, but growth factors contained in platelets can stimulate regeneration of hair follicles and other tissues as well,” says Dr. Scott.

In addition, low-level LED laser lights have been found to be helpful in regrowing hair in some cases.

It’s likely that even more treatments will be developed in the near future. There has been a significant increase in research into the causes and treatments of alopecia. Hair is one of the few structures in our body that replaces itself and is consequently being looked at as a model for cellular growth and regeneration. “Because of that, I’m confident that we will have more, and more effective, treatments on the horizon,” says Dr. Scott.

Cosmetic options for hair loss

When medical treatments fall short, women can also consider cosmetic options to make up for lost hair. A noninvasive approach is to wear a wig. At the other end of the spectrum is hair transplantation, a surgical procedure that moves active follicles from the back of the scalp to areas where the hair is thinning. Once transplanted, the hair grows normally.

Hair transplantation is typically performed as an outpatient surgical procedure. In the appropriate patient, it can be extremely successful, but it won’t work for everyone, says Dr. Scott. One drawback is the expense: it can cost thousands of dollars and is not covered by insurance. The procedure also requires recovery time. And it may not be appropriate for women who have diffuse thinning across the whole scalp. It’s more effective in treating smaller, more defined areas of balding.

Image: RobertoDavid/Getty Images

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