Several health conditions, including thyroid disease and iron deficiency anemia, 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 underlying causes in sudden or severe hair loss. Such basic health screening can be done by a family physician, internist, or gynecologist. Sometimes a scalp biopsy may be taken to help in diagnosis of severe or unexplained 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 chemotherapy and immunosuppressive medications commonly produce hair loss. Complete hair loss after chemotherapy regrows after six to 12 months.
Most people normally shed 50 to 100 hairs a day. This usually doesn’t cause noticeable thinning of scalp hair because new hair is growing in at the same time. Hair loss occurs when this cycle of hair growth and shedding is disrupted or when the hair follicle is destroyed and replaced with scar tissue.
The exact cause of hair loss may not be fully understood, but it’s usually related to one or more of the following factors:
Family history (heredity)
Family history (heredity)
The most common cause of hair loss is a hereditary condition called male-pattern baldness or female-pattern baldness. It usually occurs gradually and in predictable patterns — a receding hairline and bald spots in men and thinning hair in women.
Heredity also affects the age at which you begin to lose hair, the rate of hair loss and the extent of baldness. Pattern baldness is most common in men and can begin as early as puberty. This type of hair loss may involve both hair thinning and miniaturization (hair becomes soft, fine and short).
Hormonal changes and medical conditions
A variety of conditions can cause hair loss, including:
Patchy hair loss. This type of non-scarring hair loss is called alopecia areata. It occurs when the body’s immune system attacks hair follicles — causing sudden hair loss that leaves smooth, roundish bald patches on the skin.
Scalp infections. Infections, such as ringworm, can invade the hair and skin of your scalp, leading to scaly patches and hair loss. Once infections are treated, hair generally grows back.
Other skin disorders. Diseases that cause scarring alopecia may result in permanent loss at the scarred areas. These conditions include lichen planus, some types of lupus and sarcoidosis.
Hair-pulling disorder. This condition, also called trichotillomania, causes people to have an irresistible urge to pull out their hair, whether it’s from the scalp, the eyebrows or other areas of the body.
Hair loss can be caused by drugs used for cancer, arthritis, depression, heart problems, high blood pressure and birth control. Intake of too much vitamin A may cause hair loss as well.
Other causes of hair loss
Hair loss can also result from:
Radiation therapy to the head. The hair may not grow back the same as it was before.
A trigger event. Many people experience a general thinning of hair several months after a physical or emotional shock. This type of hair loss is temporary. Examples of trigger events include sudden or excessive weight loss, a high fever, surgery, or a death in the family.
Certain hairstyles and treatments. Excessive hairstyling or hairstyles that pull your hair tight, such as pigtails or cornrows, can cause traction alopecia. Hot oil hair treatments and permanents can cause inflammation of hair follicles that leads to hair loss. If scarring occurs, hair loss could be permanent.
TEST & DIAGNOSIS
Before making a diagnosis, your doctor will likely give you a physical exam and ask about your medical history and family history. He or she may also perform tests, such as the following:
Blood test. This may help uncover medical conditions related to hair loss, such as thyroid disease.
Pull test. Your doctor gently pulls several dozen hairs to see how many come out. This helps determine the stage of the shedding process.
Scalp biopsy. Your doctor scrapes samples from the skin or from a few hairs plucked from the scalp to examine the hair roots. This can help determine whether an infection is causing hair loss.
Light microscopy. Your doctor uses a special instrument to examine hairs trimmed at their bases. Microscopy helps uncover possible disorders of the hair shaft.
TREATMENTS & DRUGS
Effective treatments for some types of hair loss are available. But some hair loss is permanent. With some conditions, such as patchy alopecia, hair may regrow without treatment within a year.
Treatments for hair loss include medications, surgery, laser therapy, and wigs or hairpieces. Your doctor may suggest a combination of these approaches in order to get the best results.
The goals of treatment are to promote hair growth, slow hair loss or hide hair loss.
If your hair loss is caused by an underlying disease, treatment for that disease will be necessary. This may include drugs to reduce inflammation and suppress your immune system, such as prednisone. If a certain medication is causing the hair loss, your doctor may advise you to stop using it for at least three months.
Medications are available to treat pattern baldness. Two medications approved by the Food and Drug Administration (FDA) to treat hair loss are:
Minoxidil (Rogaine). Minoxidil is an over-the-counter liquid or foam that you rub into your scalp twice a day to grow hair and to prevent further hair loss. It may be used by men and women. With this treatment, some people experience hair regrowth, a slower rate of hair loss or both. The effect peaks at 16 weeks and you need to keep applying the medication to retain benefits.
Possible side effects include scalp irritation, unwanted hair growth on the adjacent skin of the face and hands, and rapid heart rate (tachycardia).
Finasteride (Propecia). This prescription drug is available only to men. It’s taken daily in pill form. Many men taking finasteride experience a slowing of hair loss, and some may show some new hair growth. You need to keep taking it to retain benefits.
Rare side effects of finasteride include diminished sex drive and sexual function and an increased risk of prostate cancer. Women who are or may be pregnant need to avoid touching crushed or broken tablets.
In the most common type of permanent hair loss, only the top of the head is affected. Hair transplant or restoration surgery can make the most of the hair you have left.
During this procedure, your surgeon removes tiny plugs of skin, each containing a few hairs, from the back or sides of your scalp. He or she then implants the plugs into the bald sections of your scalp. You may be asked to take a hair loss medication before and after surgery to improve results.
Surgical procedures to treat baldness are expensive and can be painful. Possible risks include infection and scarring.
A low-level laser device is available to treat men and women with pattern baldness. It has been cleared by the FDA. A study of 128 male and 141 female subjects indicated the device resulted in an overall improvement of hair loss condition and thickness among those who used the device. The researchers said no side effects were noted but that further study is needed to consider the long-term effects of this therapy.
Wigs and hairpieces
You may want to try a wig or a hairpiece as an alternative to medical treatment or if you don’t respond to treatment. It can be used to cover either permanent or temporary hair loss. Quality, natural-looking wigs and hairpieces are available.
If your hair loss is due to a medical condition, the cost of a wig may be covered by insurance. You’ll need a prescription for the wig from your doctor.
Some studies report that the patchy hair loss caused by alopecia areata may be helped by lavender oil combined with oils from thyme, rosemary and cedar wood. Further study is needed.
These tips may help you avoid preventable types of hair loss:
Eat a nutritionally balanced diet.
Avoid tight hairstyles, such as braids, buns or ponytails.
Avoid compulsively twisting, rubbing or pulling your hair.
Treat your hair gently when washing and brushing. A wide-toothed comb may help prevent pulling out hair.
Avoid harsh treatments such as hot rollers, curling irons, hot oil treatments and permanents.