RELATED: If You’re Over 65, Not Doing This in the Shower Is Causing Hair Loss. Most people lose an average of 50 to 100 hairs per day, according to the Mayo Clinic, but if your hair seems to be thinning, it may be a sign of male or female pattern hair loss, a genetic condition sometimes referred to as androgenetic alopecia. People with this condition lose more than the average amount of hair, and do not regrow it quickly. Doctors may be able to determine whether that’s the root cause of your hair loss by comparing your experience to that of your mother, aunts, or other women in your family. However, if there is no obvious genetic reason, experts say it could have one of several underlying causes—and doctors commonly diagnose many of them through blood tests. “If hair follicles are uniform in size, or if the hair loss is sudden, it is likely to be caused by something other than heredity, like a medical condition,” Wendy Roberts, MD, a California-based dermatologist told WebMD. She explains that some of the most common causes for female hair loss include pregnancy, thyroid disorders, anemia, autoimmune diseases (including but not limited to psoriasis), polycystic ovary syndrome (PCOS), and certain skin conditions.ae0fcc31ae342fd3a1346ebb1f342fcb RELATED: Doing This in the Shower Is Making You Lose Your Hair, Experts Warn. According to the Cleveland Clinic, many women who experience hair loss are suffering from alopecia areata, a genetic autoimmune disease in which the immune system attacks the hair follicles. “When this happens, the person’s hair begins to fall out, often in clumps the size and shape of a quarter. The extent of the hair loss varies; in some cases, it is only in a few spots. In others, the hair loss can be greater. On rare occasions, the person loses all of the hair on his or her head (alopecia areata totalis) or entire body (alopecia areata universalis),” explains the Cleveland Clinic. Alopecia areata can be an unpredictable condition. In some people with this type of hair loss, the hair grows back and falls out again in cycles. In others, the hair grows back and doesn’t fall out again. “Because there are so many reasons for hair loss, testing is sometimes necessary to make sure alopecia areata is the cause of your hair loss,” explains the American Academy of Dermatology Associate. “A blood test can look for other diseases caused by the immune system. Sometimes, other tests are necessary,” their experts add. Though more research is needed to determine the link between female hair loss and iron deficiency (anemia), “the research does suggest that iron deficiency hair loss seems to be related to hair loss that does not scar the hair follicles,” explains the site Medical News Today. “This is promising for regrowth because it means that the follicles are not severely damaged and may be able to grow hair again,” their experts add. Similarly thyroid disorders, PCOS, pregnancy, and other conditions cause thinning hair which occurs evenly across the scalp. A simple blood test should be able to tell you whether you have any of these conditions, or if you are pregnant. For more health news sent directly to your inbox, sign up for our daily newsletter. Depending on the underlying cause, there may be treatments available to help you regrow some of your hair. Your doctor will also attempt to treat the underlying cause, which can help hair regrow naturally. For instance, if the cause is autoimmune, your doctors may prescribe corticosteroid injections or topical steroids, a form of anti-inflammatory medication, or topical diphencyprone (DPCP), a form of immunotherapy. If you are found to be anemic, your doctor may instead recommend dietary changes and iron supplements, or suggest minoxidil (commercially sold as Rogaine) to treat female pattern baldness. Speak with your doctor to discuss the full range of underlying causes for hair loss and possible treatments. RELATED: If Your Hair Is Thinning, This Food Could Be to Blame, Study Says.