Hair is made of a kind of protein called keratin. A single hair has a hair shaft (the part that shows), a root below the skin, and a follicle. The follicle is the place the hair root grows from. At the lower end of the follicle is the hair bulb. This is where the hair’s color pigment, or melanin, is produced.
Hair loss (alopecia) can affect just your scalp or your entire body, and it can be temporary or permanent. It can be the result of heredity, hormonal changes, medical conditions or a normal part of aging. Anyone can lose hair on their head, but it’s more common in men.
Everyone experiences hair shedding, and it happens to each of us every day. Most people lose 50 to 100 hairs per day as part of this natural cycle, more on days you wash your hair. But what if you check your pillow, shower drain, or comb and it looks like you’re suddenly losing much more than that?
Hair loss is often distressing and can have a significant effect on the patient’s quality of life. Patients may present to their family physician first with diffuse or patchy hair loss. Scarring alopecia is best evaluated by a dermatologist. Nonscarring alopecias can be readily diagnosed and treated in the family physician’s office. Androgenetic alopecia can be diagnosed clinically and treated with minoxidil. Alopecia areata is diagnosed by typical patches of hair loss and is self-limited. Tinea capitis causes patches of alopecia that may be erythematous and scaly and must be treated systemically. Telogen effluvium is a nonscarring, noninflammatory alopecia of relatively sudden onset caused by physiologic or emotional stress. Once the precipitating cause is removed, the hair typically will regrow
While male and female pattern baldness is a primary cause of hair loss, there is a range of other reasons. A doctor will want to explore these before recommending the appropriate treatment.
Baldness typically refers to excessive hair loss from your scalp. Hereditary hair loss with age is the most common cause of baldness. Some people prefer to let their hair loss run its course untreated and unhidden. Others may cover it up with hairstyles, makeup, hats or scarves. And still others choose one of the treatments available to prevent further hair loss or restore growth.
Figuring out why you’re suddenly losing more hair than usual can be tricky because there are many different causes of hair loss in women. Some, like hereditary hair loss (androgenetic alopecia), aren’t really in your control—you get the hand you’re dealt. But others, like traction alopecia or temporary hair shedding (a very common condition called telogen effluvium), can be managed or even reversed if caught early. Making things even more complicated, some causes of hair loss in women result in sudden shedding while others may become progressively more noticeable over time.
What is Hair Loss?
The American Academy of Dermatology (AAD) notes that 80 million men and women in America have hereditary hair loss (alopecia).
It can affect just the hair on your scalp or your entire body. Although alopecia is more prevalent in older adults, excessive hair loss can occur in children as well.
It’s normal to lose between 50 and 100 hairs a day. With about 100,000 hairs on your head, that small loss isn’t noticeable.
New hair normally replaces the lost hair, but this doesn’t always happen. Hair loss can develop gradually over years or happen abruptly. Hair loss can be permanent or temporary.
It’s impossible to count the amount of hair lost on a given day. You may be losing more hair than is normal if you notice a large amount of hair in the drain after washing your hair or clumps of hair in your brush. You might also notice thinning patches of hair or baldness.
If you notice that you’re losing more hair than usual, you should discuss the problem with your doctor. They can determine the underlying cause of your hair loss and suggest appropriate treatment plans.
Hair loss can range from mild hair thinning to total baldness. Hair can fall out for many different reasons. Medically, hair loss falls into several categories, including:
- Telogen effluvium — This common form of hair loss happens two to three months after a major body stress, such as a prolonged illness, major surgery or serious infection. It also can happen after a sudden change in hormone levels, especially in women after childbirth. Moderate amounts of hair fall out from all parts of the scalp, and may be noticed on a pillow, in the tub or on a hairbrush. While hair on some parts of the scalp may appear thinner, it is rare to see large bald spots.
- Drug side effects — Hair loss can be a side effect of certain medications, including lithium, beta-blockers, warfarin, heparin, amphetamines and levodopa (Atamet, Larodopa, Sinemet). In addition, many medications used in cancer chemotherapy — such as doxorubicin (Adriamycin) — commonly cause sudden hair loss affecting the entire head.
- Symptom of a medical illness — Hair loss can be one of the symptoms of a medical illness, such as systemic lupus erythematosus (lupus), syphilis, a thyroid disorder (such as hypothyroidism or hyperthyroidism), a sex-hormone imbalance or a serious nutritional problem, especially a deficiency of protein, iron, zinc or biotin. These deficiencies are most common in people on restrictive diets and women who have very heavy menstrual flow.
- Tinea capitis (fungal infection of the scalp) — This form of patchy hair loss happens when certain types of fungi infect the scalp. This causes the hair to break off at the scalp surface and the scalp to flake or become scaly. Tinea capitis is a common form of patchy hair loss in children.
- Alopecia areata — This is an autoimmune disease that causes hair to fall out in one or more small patches. The cause of this condition is unknown, although it is more common in people who have other autoimmune diseases. When the same process causes total loss of hair from the scalp it is known as alopecia totalis.
- Traumatic alopecia — This form of hair loss is caused by hairdressing techniques that pull the hair (tight braiding or cornrowing), expose hair to extreme heat and twisting (curling iron or hot rollers) or damage the hair with strong chemicals (bleaching, hair coloring, permanent waves). In addition, some people have an uncommon psychiatric disorder (trichotillomania) in which compulsive hair pulling and twisting can cause bald spots.
- Hereditary pattern baldness, or androgenetic alopecia — In men, hair loss may follow the typical male pattern (receding front hairline and/or thinning hair at the top of the head). This is the most common type of hair loss, and it can begin at any time in a man’s life, even during his teen years. It usually is caused by the interaction of three factors: an inherited tendency toward baldness, male hormones and increasing age. Many women will develop some degree of female-pattern baldness. In women, thinning occurs over the entire top or crown of the scalp, sparing the front of the scalp.
Hair loss can appear in many different ways, depending on what’s causing it. It can come on suddenly or gradually and affect just your scalp or your whole body.
Signs and symptoms of hair loss may include:
- Gradual thinning on top of head. This is the most common type of hair loss, affecting people as they age. In men, hair often begins to recede at the hairline on the forehead. Women typically have a broadening of the part in their hair. An increasingly common hair loss pattern in older women is a receding hairline (frontal fibrosing alopecia).
- Circular or patchy bald spots. Some people lose hair in circular or patchy bald spots on the scalp, beard or eyebrows. Your skin may become itchy or painful before the hair falls out.
- Sudden loosening of hair. A physical or emotional shock can cause hair to loosen. Handfuls of hair may come out when combing or washing your hair or even after gentle tugging. This type of hair loss usually causes overall hair thinning but is temporary.
- Full-body hair loss. Some conditions and medical treatments, such as chemotherapy for cancer, can result in the loss of hair all over your body. The hair usually grows back.
- Patches of scaling that spread over the scalp. This is a sign of ringworm. It may be accompanied by broken hair, redness, swelling and, at times, oozing.
Causes Of Hair Loss
Hereditary Hair Loss
Both men and women develop this type of hair loss, which is the most common cause of hair loss worldwide. In men, it’s called male pattern hair loss. Women get female pattern hair loss. Regardless of whether it develops in a man or women, the medical term is androgenic alopecia.
No matter which term you use, it means that you’ve inherited genes that cause your hair follicles (what each hair grows out of) to shrink and eventually stop growing hair. Shrinking can begin as early as your teens, but it usually starts later in life.
In women, the first noticeable sign of hereditary hair loss is usually overall thinning or a widening part.
When a man has hereditary hair loss, the first sign is often a receding hairline or bald spot at the top of his head.
Androgenetic alopecia is another term for male or female pattern baldness. It is a very common cause of hair loss.
Both male and female pattern baldness is genetic. Males tend to lose hair from the temples and crown of the head. In females, hair usually becomes thinner all over the head.
Androgenetic alopecia is more likely to happen as a person ages but can start at any point after puberty. Many females who experience androgenetic alopecia develop it after going through the menopause. This means that hormones may have something to do with it.
It is possible to treat this condition with minoxidil, a medication for hair growth.
This kind of hair loss often shows up as round bald patches. It can make you lose hair suddenly and seemingly out of the blue, according to NYU Langone Health. The condition happens when your body’s immune system mistakenly attacks your hair follicles. Your hair may grow back on its own or with treatment, the American Academy of Dermatology says.
PCOS Can Be a Trigger
Polycystic ovary syndrome (PCOS) is a condition in women in which the body manufactures more androgens, or male hormones, than it normally should. It is a potential cause of hormonal hair loss in women. Women who suffer from this condition may grow facial hair and extra body hair. One of the other symptoms of this condition is thinning of hair on the head. Women affected with PCOS may also experience weight gain, acne, menstrual irregularities, ovulation problems, depression, and infertility. Hair thinning may be the only outward sign that a woman is suffering from this condition.
Traction alopecia is caused over time by constant pulling on hair roots. Hairstyles that cause tension on the hair follicles such as tight braids, or “corn rows,” often cause this condition. It may also be caused by chemical straightening or weaving. The sooner this condition is diagnosed the easier it is to treat, and if left untreated over a long period of time, the hair loss may become permanent. Wearing hair in styles that are looser and do not pull on the roots is often the best way to prevent this type of hair loss.
Hair Loss From Thyroid Problems
Either an underactive thyroid, a medical condition called hypothyroidism, or an overactive thyroid, or hyperthyroidism, can result in hair loss because each condition causes a hormonal imbalance. Hormones help to regulate nearly every function in the body, including hair growth. Getting the right treatment to control either of these thyroid conditions will get hormones under control, stop hair loss, and allow your hair to starting grow back.
Blame it on testosterone, at least in part, because cells in the scalps of men who are genetically disposed convert that essential male hormone into another hormone known as DHT that causes follicles to shrink and eventually stop growing hair. The hormonal changes that occur during menopause are a common cause of thinning hair in women; in men, thyroid issues can also contribute to hair loss.
Trichotillomania (pronounced: trik-o-til-uh-MAY-nee-uh)
Trichotillomania is a psychological disorder in which people repeatedly pull their hair out, often leaving bald patches. That can leave areas of baldness and damaged hairs of different lengths. People with trichotillomania usually need help from a therapist or other mental health professional before they can stop pulling their hair out.
When we think of hereditary hair loss, we usually go straight to male pattern baldness. But people of all genders are susceptible to hereditary hair loss. In women the hair loss is usually concentrated at the crown of the head (especially noticeable at the hair part), while it’s more likely to affect men along the hairline, the American Academy of Dermatology (AAD) notes.
Although you can’t prevent this type of hair loss entirely, there are treatments available—such as over-the-counter minoxidil or finasteride—that can slow it down and make hair stay fuller longer. So the sooner you start treatment, the better. Keep in mind that your treatment options for any condition or health issue on this list may change over time based on new research and newly available therapies. Make sure you have ongoing conversations with your doctor about which treatment options may be best for you.
Some women may experience excessive hair loss shortly after giving birth. This is due to a decrease in estrogen levels. This type of hair loss is a temporary condition and usually resolves within a year or sooner.
To help hair return to its normal condition, try:
- using a volumizing shampoo and conditioner
- using products designed for fine hair
- avoiding intensive conditioners or conditioning shampoos as these can be too heavy for fine hair
- applying conditioner to the ends of the hair, rather than the scalp, to avoid weighing hair down
Ringworm and Hair Loss
Ringworm is a fungal skin infection that causes patches of hair loss. The official medical name for ringworm on the scalp is tinea capitis. The infection starts out as a small pimple that grows larger. Affected areas are itchy, red, inflamed, scaly patches with temporary baldness. The skin may ooze. People may have one or more bald spots. Ringworm is more common in children, but adults can get it, too.
The fungus triggers hair loss by causing hair to become brittle and to break off. The skin often appears most red around the edge of the lesion, with a more normal appearing skin tone in the center. That is one of the reasons the condition is called ringworm. The condition is contagious with skin-to-skin contact. It is also transmissible by infected combs, hairbrushes, unwashed clothing, and surfaces in gyms, showers, and pool areas. Your doctor can treat ringworm with oral antifungal medication. Ringworm on the scalp is one potential cause of hair loss in women that is reversible.
Hair Loss Due to Medications
Hair loss is a side effect of a number of medications taken for common health problems. Blood-thinning medications, oral contraceptives, drugs for depression, NSAIDs, and beta and calcium channel blockers can all lead to thinning hair or baldness. Too much vitamin A and vitamin A-based drugs called retinoids can cause hair loss as well. Some chemotherapy drugs used to treat cancer are known to cause total hair loss as they work to destroy cancer cells. Just as hair usually grows back after chemo, it should also grow back once you stop taking any medication that causes hair loss.
Not eating enough healthy food can contribute to hair loss. This is why some people with eating disorders like anorexia and bulimia lose their hair: The body isn’t getting enough protein, vitamins, and minerals to support hair growth. Some teens who are vegetarians also lose their hair if they don’t get enough protein from non-meat sources. And some athletes are at higher risk for hair loss because they may be more likely to develop iron-deficiency anemia.
Disruption Of The Hair Growth Cycle
Some major events can alter the hair’s growth cycle temporarily. For example, delivering a baby, having surgery, going through a traumatic event, or having a serious illness or high fever can temporarily cause shedding of large amounts of hair. Because the hair we see on our heads has actually taken months to grow, a person might not notice any disruption of the hair growth cycle until months after the event that caused it. This type of hair loss corrects itself.
Dandruff or scalp psoriasis
When the skin on the scalp is inflamed and itchy, it’s obviously tempting to scratch it. But that may cause your hair to shed more than usual.
Dandruff is the most easily treated cause of hair loss, Dr. Fusco says, because you can treat it with over-the-counter products, like a shampoo containing zinc pyrithione or exfoliating ingredients such as the classic Head & Shoulders Classic ($9, Amazon) or Oribe Serene Scalp Anti-Dandruff Shampoo ($46, Dermstore). “Consistency is the trick,” Dr. Fusco says, so it’s important to find a shampoo and conditioner you like enough to use regularly.
But other conditions can also cause itchiness and scalp flaking, including seborrheic dermatitis (a more severe version of dandruff caused by a buildup of yeast and oil) and psoriasis (an autoimmune condition that causes thick patches of skin). Treating these issues may take more time and effort than dandruff, so it’s important to check in with a dermatologist if you think you may be dealing with one of these conditions.
“An autoimmune condition makes the body recognize its own hair follicles as foreign and it attacks them and makes the hair fall out,” Dr. Fusco explains.
This could be a condition like alopecia areata, in which the immune system attacks the hair follicles. Sometimes people with alopecia areata do see their hair grow back (although it may fall out again). But if not, dermatologists can help by prescribing various treatments, like corticosteroid injection to stimulate hair growth, the AAD says.
Conditions that primarily affect another part of the body—like thyroid disease, rheumatoid arthritis, or sickle-cell anemia—can also cause hair loss as one of many symptoms. Additionally, Dr. Schlosser notes that lupus can cause some scarring of the hair follicle, resulting in permanent hair loss.
These conditions can be serious and require an accurate diagnosis from an experienced health care provider. So if you think your hair loss may be connected to an underlying issue like an autoimmune condition, it’s important to talk to your doctor.
Overprocessing Your Hair
Getting frequent perms, chemical straightening procedures, or relaxing procedures—basically anything that uses harsh chemicals on your scalp and hair—can damage the hair follicle and cause permanent hair loss. “After repeated insults, the hair follicles just won’t grow back,” Dr. Schlosser says. This can cause hair to appear thinner, and may be especially noticeable on the scalp.
You can prevent further damage by avoiding those harsh procedures and using products designed to help hydrate and heal your hair and scalp. But if you want your hair to grow back, you’ll likely need to enlist the guidance of a board-certified dermatologist.
How Is Hair Loss Diagnosed?
Persistent hair loss often indicates an underlying health issue.
Your doctor or dermatologist can determine the cause of your hair loss based on a physical examination and your health history. In some cases, simple dietary changes can help. Your doctor may also change your prescription medications.
If your dermatologist suspects an autoimmune or skin disease, they might take a biopsy of the skin on your scalp.
This will involve carefully removing a small section of skin for laboratory testing. It’s important to keep in mind that hair growth is a complex process. It may take time to determine the exact cause of your hair loss.
There are few scientifically proven and FDA-approved treatments for hair loss. There are thousands of unproven claims and products to help with hair regrowth. Many conditioners, shampoos, vitamins, and other products claim to help hair grow in some unspecified way. Nioxin has been a popular brand of shampoo for hair loss, but there is no compelling evidence showing it is any more effective than regular shampoos. These products are usually harmless but generally not scientifically proven and therefore potentially useless. To slow down hair loss, there are at least four potentially effective, basic options. These include medications like Minoxidil, and Propecia, which are for long-term use. Stopping these drugs does not seem to worsen or exacerbate the prior hair loss. The patient will simply revert to the state he would have been in had he never started treatment.
- Minoxidil (Rogaine): This topical medication is available over the counter, and no prescription is required. Men and women can use it. It works best on the crown, less on the frontal region. Minoxidil is available as a 2% solution, 4% solution, an extra-strength 5% solution, and a new foam or mousse preparation. Rogaine may grow a little hair, but it’s better at holding onto what’s still there. There are few side effects with Rogaine. The main problem with this treatment is the need to keep applying it once or twice daily, and most men get tired of it after a while. In addition, minoxidil tends to work less well on the front of the head, which is where baldness bothers most men. Inadvertent application to the face or neck skin can cause unwanted hair growth in those areas.
- Finasteride (Propecia): This medication is FDA approved for use in only men with androgenic hair loss. Finasteride is in a class of medications called 5-alpha reductase inhibitors. It helps reduce hair loss by blocking the action of natural hormones in scalp hair follicles. Propecia is a lower-dose version of a commercially available drug called Proscar that helps shrink enlarged prostates in middle-aged and older men. Women of child-bearing potential should avoid finasteride. Propecia 1 mg tablets are available by prescription and taken once daily. Propecia may grow and thicken hair to some extent for some people, but its main use is to keep (maintain) hair that’s still there. Studies have shown that this medication works well in some types of hair loss, and patients should use it for about six to 12 months before full effects are determined. This medication does not “work” in days to weeks, and its onset of visible improvement tends to be gradual. It may be best for men who still have enough hair to retain but also can help some regrow hair. Possible but very unlikely side effects include impotence or a decreased sex drive (libido). Studies show that these side effects were possibly slightly more common than seen in the general population and are reversible when patients stop taking the drug. The cost is about $70-$100/month, and most health insurers do not reimburse for the expense.
- A group of topical medications called prostaglandin analogs have recently began undergoing testing for potential hair regrowth. They may be used in men and women. These drugs are not currently FDA approved for scalp hair loss. Currently, these are primarily used for eyelash enhancement. One of the new medications is called bimatoprost (Latisse). Further testing and studies are required to assess the efficacy of these products in scalp hair loss. Bimatoprost solution is sometimes used off-label for help in selected cases of hair loss. It is currently FDA approved for cosmetic eyelash enhancement. Studies have shown it can treat hypotrichosis (short or sparse) of the eyelashes by increasing their growth, including length, thickness, and darkness. This medication is also commercially available as Lumigan, which is used to treat glaucoma. It is not known exactly how this medication works in hair regrowth, but it is thought to lengthen the anagen phase (active phase) of hair growth. Interestingly, during routine medical use of Lumigan eyedrops for glaucoma patients, it was serendipitously found that eyelashes got longer and thicker in many users. This led to clinical trials and the approval of cosmetic use of Latisse for eyelashes.