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.

When to see a doctor

See your doctor if you are distressed by persistent hair loss in you or your child and want to pursue treatment. For women who are experiencing a receding hairline (frontal fibrosing alopecia), talk with your doctor about early treatment to avoid significant permanent baldness.

Also talk to your doctor if you notice sudden or patchy hair loss or more than usual hair loss when combing or washing your or your child's hair. Sudden hair loss can signal an underlying medical condition that requires treatment.

People typically lose 50 to 100 hairs a day. This usually isn't noticeable because new hair is growing in at the same time. Hair loss occurs when new hair doesn't replace the hair that has fallen out.

Hair loss is typically related to one or more of the following factors:

• Family history (heredity). The most common cause of hair loss is a hereditary condition that happens with aging. This condition is called androgenic alopecia, male-pattern baldness and female-pattern baldness. It usually occurs gradually and in predictable patterns — a receding hairline and bald spots in men and thinning hair along the crown of the scalp in women.
• Hormonal changes and medical conditions. A variety of conditions can cause permanent or temporary hair loss, including hormonal changes due to pregnancy, childbirth, menopause and thyroid problems. Medical conditions include alopecia areata (al-o-PEE-she-uh ar-e-A-tuh), which is immune system related and causes patchy hair loss, scalp infections such as ringworm, and a hair-pulling disorder called trichotillomania (trik-o-til-o-MAY-nee-uh).
• Medications and supplements. Hair loss can be a side effect of certain drugs, such as those used for cancer, arthritis, depression, heart problems, gout and high blood pressure.
• Radiation therapy to the head. The hair may not grow back the same as it was before.
• A very stressful event. Many people experience a general thinning of hair several months after a physical or emotional shock. This type of hair loss is temporary.
• Hairstyles and treatments. Excessive hairstyling or hairstyles that pull your hair tight, such as pigtails or cornrows, can cause a type of hair loss called traction alopecia. Hot-oil hair treatments and permanents also can cause hair to fall out. If scarring occurs, hair loss could be permanent.

A number of factors can increase your risk of hair loss, including:

• A family history of balding on your mother's or father's side
• Age
• Significant weight loss
• Certain medical conditions, such as diabetes and lupus
• Stress
• Poor nutrition

Most baldness is caused by genetics (male-pattern baldness and female-pattern baldness). This type of hair loss is not preventable.

These tips may help you avoid preventable types of hair loss:

• Be gentle with your hair. Use a detangler and avoid tugging when brushing and combing, especially when your hair is wet. A wide-toothed comb might help prevent pulling out hair. Avoid harsh treatments such as hot rollers, curling irons, hot-oil treatments and permanents. Limit the tension on hair from styles that use rubber bands, barrettes and braids.
• Ask your doctor about medications and supplements you take that might cause hair loss.
• Protect your hair from sunlight and other sources of ultraviolet light.
• Stop smoking. Some studies show an association between smoking and baldness in men.
• If you're being treated with chemotherapy, ask your doctor about a cooling cap. This cap can reduce your risk of losing hair during chemotherapy.

Before making a diagnosis, your doctor will likely give you a physical exam and ask about your diet, your hair care routine, and your medical and family history. You might also have tests, such as the following:

• Blood test. This might help uncover medical conditions that can cause hair loss.
• 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 under a microscope. 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.

Effective treatments for some types of hair loss are available. You might be able to reverse hair loss, or at least slow it. With some conditions, such as patchy hair loss (alopecia areata), hair may regrow without treatment within a year. Treatments for hair loss include medications and surgery.

Medication

If your hair loss is caused by an underlying disease, treatment for that disease will be necessary. If a certain medication is causing the hair loss, your doctor may advise you to stop using it for a few months.

Medications are available to treat pattern (hereditary) baldness. The most common options include:

• Minoxidil (Rogaine). Over-the-counter (nonprescription) minoxidil comes in liquid, foam and shampoo forms. To be most effective, apply the product to the scalp skin once daily for women and twice daily for men. Many people prefer the foam applied when the hair is wet.

  Products with minoxidil help many people regrow their hair or slow the rate of hair loss or both. It'll take at least six months of treatment to prevent further hair loss and to start hair regrowth. It may take a few more months to tell whether the treatment is working for you. If it is helping, you'll need to continue using the medicine indefinitely to retain the benefits.

  Possible side effects include scalp irritation and unwanted hair growth on the adjacent skin of the face and hands.

• Finasteride (Propecia). This is a prescription drug for men. You take it daily as a pill. Many men taking finasteride experience a slowing of hair loss, and some may show new hair growth. It may take a few months to tell whether it's working for you. You'll need to keep taking it to retain any benefits. Finasteride may not work as well for men over 60.

  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.

• Other medications. Other oral options include spironolactone (Carospir, Aldactone) and oral dutasteride (Avodart).

Hair transplant surgery

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 a hair transplant procedure, a dermatologist or cosmetic surgeon removes hair from a part of the head that has hair and transplants it to a bald spot. Each patch of hair has one to several hairs (micrografts and minigrafts). Sometimes a larger strip of skin containing multiple hair groupings is taken. This procedure doesn't require hospitalization, but it is painful so you'll be given a sedation medicine to ease any discomfort. Possible risks include bleeding, bruising, swelling and infection. You may need more than one surgery to get the effect you want. Hereditary hair loss will eventually progress despite surgery.

Surgical procedures to treat baldness are not usually covered by insurance.

Laser therapy

The Food and Drug Administration has approved a low-level laser device as a treatment for hereditary hair loss in men and women. A few small studies have shown that it improves hair density. More studies are needed to show long-term effects.

You might want to try various hair care methods to find one that makes you feel better about how you look. For example, use styling products that add volume, color your hair, choose a hairstyle that makes a widening part less noticeable. Use wigs or extensions, or shave your head. Talk with a hair stylist for ideas. These approaches can be used to address permanent or temporary hair loss.

If your hair loss is due to a medical condition, the cost of a wig might be covered by insurance.

You're likely to first bring your concerns to the attention of your family doctor. He or she may refer you to a doctor who specializes in the treatment of skin problems (dermatologist).

What you can do

• List key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins and supplements that you're taking.
• List questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For hair loss, some basic questions to ask your doctor include:

• What is causing my hair loss?
• Are there other possible causes?
• What kinds of tests do I need?
• Is my hair loss permanent or will it grow back? How long will it take? Will it have a different texture after it grows back?
• What is the best course of action?
• Should I change my diet or hair care routine?
• Are there any restrictions that I need to follow?
• Should I see a specialist? What will that cost, and will my insurance cover seeing a specialist?
• Is there a generic alternative to the medicine you're prescribing me?
• Do you have any brochures or other printed material that I can take home with me?
• What websites do you recommend?

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

• When did you first begin experiencing hair loss?
• Has your hair loss been continuous or occasional?
• Have you noticed poor hair growth, hair breakage or hair shedding?
• Has your hair loss been patchy or overall?
• Have you had a similar problem in the past?
• Has anyone in your immediate family experienced hair loss?
• What medications or supplements do you take regularly?
• What, if anything, seems to improve your hair loss?
• What, if anything, appears to worsen your hair loss?