text: What is generalized (diffuse) hair loss?
  Hair loss without scarring of the scalp is a common condition that affects most people at some time in their lives. The medical term for hair loss is alopecia.
  Generalized (diffuse) hair loss is an overall hair thinning without specific bald spots or patterns. While this type of hair loss may not be noticeable to others, often the individual will feel their hair is not as thick or full as it previously was.
  Common conditions in this category include:
  - Telogen effluvium (rapid shedding after childbirth, fever, or sudden weight loss)
  - Androgenetic or androgenic hair loss ("male-pattern baldness," "female-pattern baldness")
  What are the two types of non-scarring hair loss?
  1. Patchy hair loss
  Some conditions produce small areas of hair loss, while others affect large areas of the scalp.
  Common causes of patchy hair loss are:
  - Alopecia areata (small circular or coin size bald patches on the scalp that usually grow back within months)
  - Traction alopecia (thinning from tight braids or ponytails)
  - Trichotillomania (the habit of twisting or pulling hair out)
  - Tinea capitis (fungal infection)
  - Secondary syphilis
  2. Diffuse hair loss
  Some common causes of diffuse hair loss are:
  - Pattern alopecia
  - Drug-induced alopecia
  - Protein malnutrition
  - Systemic disease-induced alopecia (cancer, endocrine disease, and telogen effluvium)
  What is alopecia areata?
  Alopecia areata is an autoimmune condition in which the body attacks its hair follicles. Most people with alopecia areata do not have systemic problems and need no medical tests. While people frequently blame alopecia areata on “stress,” in fact, it may be the other way around; that is, having alopecia may cause stress.
  - A common skin condition, alopecia areata usually starts as a single quarter-sized circle of perfectly smooth bald skin.
  - These patches usually regrow in three to six months without treatment.
  - Sometimes, white hair temporarily regrows and then becomes dark. The most extensive form is alopecia totalis, in which the entire scalp goes bald. It's important to emphasize that patients who have localized hair loss generally don't go on to lose hair all over the scalp.
  - Alopecia areata can affect hair on other parts of the body, too (for example, the beard or eyebrows).
  Alopecia areata treatment
  - Treatments for alopecia areata include injecting small amounts of steroids such as triamcinolone into affected patches to stimulate hair growth.
  - Although localized injections may not be practical for large areas, often this is a very effective treatment in helping the hairs return sooner.
  - Other treatments, such as oral steroids, other immunosuppressives, or ultraviolet light therapy, are available for more widespread or severe cases but may be impractical for most patients because of potential side effects or risks.
  - In most mild cases, patients can easily cover up or comb over the affected areas.
  - In more severe and chronic cases, some patients wear hairpieces and some men shave their whole scalp now that this look has become fashionable.
  - Recently, investigators have noted some beneficial results in small groups of patients with extensive alopecia areata or alopecia totalis treated with a JAK1/2 inhibitor, baricitinib (Olumiant). Long-term studies are underway.
  What is traction alopecia?
  This is a small or localized hair loss area caused by repetitive or persistent pulling or traction on hair roots.
  - Tight braids and ponytails can pull hard enough on hair to make them fall out. If this happens, choosing hairstyles that put less tension on the hair is best.
  - Doing this sooner helps to avoid permanent damage.
  What is trichotillomania?
  This refers to the habitual pulling or twisting of one’s hair. The scalp and eyelashes are often affected. Unlike alopecia areata patches, which are perfectly smooth, hair patches in trichotillomania show broken-off hairs.
  - Treatment is often entirely behavioral.
  - One has to notice the behavior and then consciously stop.
  - Severe or resistant cases may require stress counseling with a therapist or psychologist or medical treatment with a psychiatrist.
  - Several antidepressant or anti-anxiety medications can help with this condition.
  What is tinea capitis?
  Tinea is the medical word for fungal infection, and capitis means head. Tinea capitis is a fungal infection of the scalp that for the most part affects school-age children.
  - Tinea capitis is more common in black African or African-American scalps.
  - This condition is rare in healthy adults.
  - Bald spots usually show broken-off hairs accompanied by dermatitis.
  - Oral antifungals can penetrate the hair roots and cure the infection, after which hair grows back.
  - Sharing hats or combs and brushes may transmit tinea capitis.
  What is telogen effluvium?
  Under normal conditions, scalp hairs live for about three years (the anagen, or growing, phase); they then enter the telogen or resting phase. During the three-month telogen period, the hair root shrivels up into a small “club,” and then the hair falls out. It is normal to lose about 100 hairs every day, and more of them on days when shampooing loosens the hairs ready to fall out. The body then replaces the hair.
  Sometimes people who worry about losing their hair start noticing hairs on their pillow or in the sink, not realizing they've always been there. A close look at these will usually reveal the club at the end, showing these hairs are shed normally.
  - Normally, about 10% of scalp hairs are in the telogen phase.
  Several circumstances produce a “shock to the system” that alters hair growth rhythm. As a result, as much as 30%-40% of the hairs can cycle into telogen. Three months later, hairs come out in a massive shedding (effluvium), especially near the front of the scalp. These include:
  - High fever
  - Sudden weight loss (crash dieting)
  - Severe illness
  - Severe emotional stress or loss
  None of these need to be life-threatening, nor does hair loss usually follow them. (Moreover, it can happen after one pregnancy, but not the next.) But when the hair falls out, it's all over the place – covering the pillow, clogging the drain, and so forth. Paradoxically, the more dramatic the hair loss, the better the prognosis, because when the body gets back into normal rhythm, most, if not all, of that hair comes back; these people need no special treatment. Normal shampooing can continue because this only loosens hairs that were going to come out anyway.
  See pictures of hair loss and other scalp related conditions See ImagesWhat are causes and risk factors for hair loss?
  Because there are many types of hair loss, finding the cause can be challenging. This review will cover the most common causes of hair loss occurring on normal, unscarred scalp skin.
  - Most hair loss is not associated with systemic or internal disease, nor is poor diet a frequent factor. Hair may simply thin as a result of predetermined genetic factors and the overall aging process.
  - Many men and women may notice mild physiologic thinning of hair starting in their 30s and 40s.
  - Life changes may cause hair loss, including:
  - Several health conditions, including thyroid disease, iron deficiency anemia, and secondary syphilis, can cause hair loss.
  - While thyroid blood tests and other lab tests, including a complete blood count (CBC), on people who have ordinary hair loss are usually normal, it is important to exclude treatable causes of hair loss.
  - Although many medications list “hair loss” among their potential side effects, most drugs are not likely to induce hair loss.
  - On the other hand, cancer treatment (for example, chemotherapy or radiation therapy) and immunosuppressive medications commonly produce hair loss.
  - Complete hair loss after chemotherapy usually regrows after six to 12 months.
  Can itchy scalp cause hair loss?
  Itchy scalp may be a symptom of a scalp disease that could produce hair loss. Causes may include seborrheic dermatitis (dandruff) and psoriasis.
  Treatments may include:
  - medicated shampoos like ketoconazole (Nizoral),
  - over-the-counter (OTC) dandruff shampoos, and
  - topical steroid creams and lotions to help decrease itching.
  Can pregnancy cause hair loss?
  Pregnancy may cause many changes in the scalp hair. As hormones fluctuate during pregnancy, a large number of women feel their hair thickens and becomes fuller.
  - This may be related to a change in the number of hairs cycling in the growth phase of hair growth, but the exact reason is unknown.
  - Quite often, there may be a loss of hair (telogen effluvium) after delivery or a few months later which will eventually normalize.
  What is androgenetic or androgenic alopecia (“male-pattern baldness,” “female-pattern baldness”)?
  This type of alopecia is often attributed to genetic predisposition and family history. Androgenic alopecia appears in both men and women. Hair loss in men is often faster, has an earlier onset, and is more extensive.
  Doctors refer to common baldness as “androgenetic alopecia” or “androgenic alopecia,” which implies a combination of hormones and heredity (genetics) is necessary to develop the condition. The exact cause of this pattern is unknown. (The male hormones involved are present in both men and women.)
  Even men who never “go bald” thin out somewhat over the years. Unlike those with reversible telogen shedding, those with common male-pattern hair loss don't notice much hair coming out; they just see it's not there anymore. Adolescent boys may notice some receding near the temples as their hairlines change from the straight-across boys' pattern to the more “M-shaped” pattern of adult men. This normal development does not mean they are losing hair.
  Some “myths” about male-pattern baldness
  - People inherit baldness through their mother’s male relatives. Genes from both the mother and the father determine baldness. Looking at one’s family can give someone at best an educated guess about how he or she will turn out. Studies are ongoing in this field, and current research has been inconclusive about the inheritance patterns.
  - Longer hair puts a strain on roots. It doesn't. And hats don't choke off the circulation to the scalp to cause hair loss either.
  - Shampooing does not accelerate balding.
  - “Poor circulation” does not cause hair loss, and massaging doesn't stop it.
  Is hair loss in women different than men?
  Women lose hair on an inherited (genetic) basis, too, but female pattern hair loss tends to be more diffuse, with less likelihood of the crown and frontal hairline being lost.
  - Although some women may notice hair thinning as early as their 20s, the pace of hair loss tends to be gradual, often taking years to become obvious to others.
  - There seems to be a normal physiologic thinning that comes with age and occurs in many women in their early to mid-30s.
  - More women have underlying causes of hair loss than men. These include treatable conditions such as anemia, thyroid disease, and polycystic ovary syndrome (PCOS).
  - These conditions are diagnosed by blood tests along with historical and physical evidence.
  - Although a few studies have suggested female baldness may be inherited through the mother's family genes, these theories require further testing.
  - Current studies are inconclusive. Although not indicated for female pattern balding, spironolactone (Aldactone) has had some success in treating this condition.
  While stories about hats choking off follicles or long hair pulling on the roots may be more folklore, repeat hair trauma as tightly woven hair pulled back and consistent friction can potentially worsen or cause localized hair loss in some individuals. Individuals who pull their hair tightly back in a rubber band can develop localized hair loss at the front of the scalp.
  Hair loss “myths” of special concern to women
  - Longer hair does not necessarily put a strain on roots.
  - Shampooing does not accelerate hair loss; it just removes those that were ready to fall out anyway.
  - Coloring, perming, and conditioning the hair do not usually cause hair loss. Burns or severe processing may produce hair fragility and breakage. Styles that pull tight may cause some loss, but hair coloring and “chemicals” usually don't.
  See SlideshowWhat types of doctors diagnose and treat hair loss?
  A family physician, internist, or gynecologist can perform a basic health screening. Dermatologists are doctors who specialize in problems of skin, hair, and nails and may provide more advanced diagnoses and treatments for hair thinning and loss. Sometimes a scalp biopsy may be necessary.
  How do physicians classify hair loss?
  There are numerous ways to categorize hair loss.
  - The scalp is examined to determine if hair loss is due to the physical destruction and loss of hair follicles (scarring or cicatricial alopecia). If the scalp appears perfectly normal with plenty of empty hair follicles, this is called non-scarring hair loss.
  - On the other hand, cicatricial alopecia permanently destroys the follicles.
  - Non-scarring hair loss also happens in situations where there is physical or chemical damage to the hair shaft, resulting in breakage. Occasionally, it may be necessary to do a biopsy of the scalp to distinguish these conditions.
  - Sometimes, a physician may pull a hair to examine the appearance of the hair shaft as well as the percentage of growing hairs (anagen phase). This article concentrates on non-scarring types of hair loss.
  What treatment is there for hair loss in men?
  There are few scientifically proven and FDA-approved treatments for hair loss.
  To slow down hair loss, there are at least four potentially effective, basic options. These include medications such as minoxidil (Rogaine), and finasteride (Propecia), which are for long-term use. Stopping these drugs does not seem to worsen or exacerbate 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, a 4% solution, an extra-strength 5% solution, and a new foam or mousse preparation. Minoxidil may grow a little hair, but it's better at holding onto what's still there. There are few side effects with minoxidil. 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. Finasteride 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. Finasteride 1 mg tablets are available by prescription and taken once daily. Finasteride 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 helps 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 $10-$60/month, and most health insurers do not reimburse for the expense.
  - A group of topical medications called prostaglandin analogs is 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 the cosmetic use of Latisse for eyelashes.
  There are thousands of unproven claims and products to help with hair regrowth. These products are usually harmless but generally not scientifically proven and therefore potentially useless.
  - 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.
  What specific treatments are there for hair loss in women?
  Female hair loss treatments include:
  - Minoxidil (Rogaine)
  - Hair transplants
  - Hair-powder fibers like Toppik
  - Hair extensions
  Minoxidil (Rogaine) is available over the counter and available in 2%, 4%, and 5% concentrations. It may be something of a nuisance to apply twice daily, but it has been shown to help conserve hair and may even grow some.
  - Minoxidil tends to grow very fine small hairs wherever it is applied. It is important to avoid running the liquid onto the face or neck where it can also grow hair.
  - It is marketed for women at the 2% concentration but may be used in higher strengths as directed by a doctor.
  Surgical procedures such as hair transplants can be useful for some women as well as men to "fill in" thinned-out areas.
  What other options do people have for hair loss?
  There are many options and alternative cosmetic treatments for hair loss. Some of these include hair-fiber powders, hairpieces, synthetic wigs, human hair wigs, hair extensions, hair weaves, lasers, and surgery.
  - Hair-fiber powders: Colored, powdery fiber sprinkles are commercially available and may work to camouflage balding areas. These colored sprinkles have special properties that help them attach to hair and give a fuller appearance. Toppik is one manufacturer of these products and can be found online. These cosmetic products are available without a prescription, are fairly inexpensive ($10-$40 range), and are quite safe with minimal risk. Often these may be used in addition to medical treatments like Rogaine, Propecia, and hair transplants, and they are a great temporary measure to tide one over for special occasions.
  - Hairpieces: Among the time-honored ways to add hair temporarily are hairpieces or hair weaving, in which a mesh is attached to the remaining hair and artificial or human hair of similar color and texture is woven with existing hair. Quality varies considerably with price; also, hairpieces and weaves may stretch, oxidize, and loosen.
  - Surgery or hair transplants: Surgical hair restoration approaches include various versions of hair transplantation (taking hair from the back and putting it near the front) or scalp reduction (cutting away bald areas and stitching the rest together). Transplant procedures have improved greatly in recent years. They can produce much more attractive and natural-looking results than older methods that sometimes leave a "checkerboard" or hair plug look. Many transplant patients now take Propecia to maintain or keep what they've transplanted. When considering a hair transplant, check the surgeon's credentials and experience carefully. Micrografts are some of the newest techniques whereby surgeons transplant single one to two hair follicles. Hair transplants may be very expensive and time-consuming procedures ranging widely anywhere from $1,000-$20,000, depending on the number of hair grafts transplanted. Typically, 500 or more hairs may be transplanted in a session.
  - Low-level laser devices approved by the FDA are promoted for use in male pattern hair loss. These devices are used at home without a physician's prescription and vary in cost from $50 to over $1,000. They come in the form of combs, helmets, and hats. Limited studies are moderately persuasive in that they stimulate hair growth.
  - Platelet-rich plasma obtained from the processed whole blood of male patients with pattern hair loss and then reinjected into their scalp has been suggested as an adjuvant treatment. The efficacy of this form of therapy is currently under investigation
  Are there home remedies for hair loss?
  A good daily multivitamin containing zinc, vitamin B, folate, iron, and calcium is a reasonable choice, although there is no good evidence that vitamins have any meaningful benefit in alopecia.
  - Newer studies suggest that vitamin D may be somewhat helpful and worth considering.
  - Specific vitamin and mineral deficiencies such as iron or vitamin B12 may be diagnosed by blood tests and treated.
  - Biotin has been promoted for hair growth, but solid scientific studies for many of these claims are lacking. While taking biotin and other supplements marketed for hair, skin, and nails probably won't worsen anything, it may also not necessarily help the situation. There is only anecdotal evidence that oral or topical application of garlic, onion juice, saw palmetto, coconut oil, evening primrose oil, apple cider vinegar, creatine, and pumpkin seed oil are of benefit for hair loss.
  Advertised hair growth supplements should be approached with mild caution. Talk to your doctor about any supplements you take.
  What is the prognosis for hair loss?
  The prognosis for androgenic non-scarring hair loss is guarded because there is no cure for the problem. Medications must be taken indefinitely. Other types of hair loss have a good chance of spontaneously resolving.
  How do people prevent hair loss?
  Hair-loss prevention depends on the underlying cause.
  - Good hair hygiene with regular shampooing is a basic step but is probably of little benefit.
  - Good nutrition, especially adequate levels of iron and vitamin B, is helpful.
  - Treatment of underlying medical conditions like thyroid disease, anemia, and hormonal imbalances may be useful in prevention.
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