If you’ve lived your life up until now with a full head of hair, it raises an eyebrow when you suddenly start to lose it. You might discover that your hairline is receding at a rate too fast for comfort, or the shower drain is always clogged with hair. If this is happening, you’re not alone. Almost 4 out of 10 men will experience significant hair loss and up to 1 in 4 women.

Hair loss isn’t the end of the world and there are things you can do about it, but there are also lots of misperceptions about the loss of hair, why it happens, and what it means. Here are some of the most common ideas about hair loss and whether they’re a myth or a fact.

Myth or Fact: Brushing Your Hair Too Much Causes Hair Loss

Myth. If you have a healthy scalp and hair, no amount of brushing will lead to significant hair loss. Other misperceptions are that hair loss is caused by wearing a hat, taking hot showers, or not keeping your hair clean. None of these are significant contributors to hair loss.

Most hair loss is genetic, due to androgenetic alopecia or male-pattern baldness. Even though you inherit the tendency, hair loss may not show up until middle-age or older. Androgenetic alopecia usually starts with a receding hairline and general thinning of the hair. However, men may experience a visible bald patch on the back of their head. Androgenetic alopecia can cause hair loss in women too, but the thinning is usually diffuse across the scalp. Women are usually spared discrete bald spots.

In people who are genetically susceptible to androgenetic alopecia, the male hormone, testosterone, plays a role. Testosterone converts to dihydrotestosterone (DHT) and this causes the hair follicles to shrink, leading to hair loss.

Myth or Fact: You Inherit Hair Loss from Your Father

Myth: You can inherit androgenetic alopecia from your mother or father’s side of the family. However, since inheritance of this condition is through dominant inheritance patterns, you’re more likely to experience it if you have a number of males in your family who have it.  There isn’t a single gene that determines whether you get this condition. Susceptibility is caused by the interaction between more than one gene.

Myth or Fact: Stress Can Cause Hair Loss

Fact. Even though androgenetic alopecia is the most common cause of hair loss, chronic physical and mental stress can cause hair thinning too. Another common cause in young women is excessive calorie restriction, leading to nutritional deficiency. Less appreciated is the fact that some medications and medical conditions can cause hair loss. One of the most common health conditions that causes thinning hair is hypothyroidism, the medical term for an under-active thyroid gland. A simple blood test can determine whether you have it. Some autoimmune conditions can also cause hair thinning or hair loss. These causes are less common than androgenetic alopecia.

Myth or Fact: Vitamins Can Stop Hair Loss

Mostly a myth. If you’re deficient in certain vitamins, supplementing with that vitamin may prevent further hair loss. However, taking supplements when you aren’t deficient will have little effect.  Some vitamin deficiencies that may cause hair loss include deficiency of B-vitamins, including riboflavin, biotin, folate, and vitamin B12. Low vitamin D can also cause hair loss in some people. Mineral deficiencies linked with hair loss include iron, selenium and zinc. Unless you’re deficient, don’t count on a supplement to make a difference.

Myth or Fact: Some Medications Can Help with Hair Loss

Fact. A drug called finasteride blocks the conversion of testosterone to DHT, thereby preventing shrinkage of the hair follicles. If you don’t like the idea of taking an oral medication, you have another option, minoxidil topical cream or gel, which you apply to your head. The active ingredient dilates blood vessels in the scalp, thereby reducing hair loss. Using it consistently can lead to regrowth, but once you start, don’t stop or the hair loss will recur.

Myth or Fact: If the Above Treatments Don’t Work, You’re Out of Luck

Myth. If minoxidil and finasteride don’t work, you have other options. Another alternative is a laser hair comb, a special comb approved by the FDA that uses a laser to stimulate the shrinking hair follicles. The comb also increases blood flow to the scalp and stimulates the production of a hormone called ADP. This combination of events stimulates hair growth. However, it won’t cause new hair to grow in areas that are already bald. The results people get with these combs vary widely.

If you have bald areas that aren’t responding to any treatments, your best option might be a hair transplant. This procedure takes hair from areas that have enough hair and places them where they’re needed, in balding areas. If there isn’t enough available hair, the surgeon can even use hair from a beard. The downside to a hair transplant, other than the cost, is you won’t get a full head of hair until at least a year has passed. The hair first grows in thin, breaks off, and grows in again thicker.

The Bottom Line

Hair loss is something you can treat these days, so you don’t have to bemoan the loss of every strand. Be sure you’re doing the basics to keep your hair and scalp healthy. If you have long hair, don’t pull it back into a tight ponytail. This places added stress on the scalp and can lead to reversible hair loss. Eat a nutrient-dense diet and don’t go on a very low-calorie diet. Learn techniques for managing stress and see your physician regularly to make sure you don’t have a health problem that causes hair loss. Also, ask your physician to review your medications and make sure you’re not taking one that causes hair thinning. Keep in mind that it’s normal to lose 50 to 100 hairs per day.