In an age where Botox derms and Brazilian waxers are readily discussed, there are few beauty taboos left.While it certainly seems like we’ve seen it all (hello Kardashian bikini line!), one thing that’s still swept under the rug, er, so to speak? “Hair loss in women is different because unlike men, women aren’t expected to go bald,” explains Robert Bernstein, M.D., founder of the prestigious Bernstein Medical Center for Hair Restoration in New York City.But while the stigma associated with female hair thinning and loss makes the subject feel taboo, it’s an extremely common complaint. “There’s a misconception that hair loss in women is rare,” Bernstein continues. Truth is, 30 percent of women will experience some form of thinning, whether they’re dishing about it on Facebook or not.QUIZ: Measure the Health of Your HairCompounding the issue? “For women, the underlying causes can be a more complicated issue,” he says. Your scalp contains about 100,000 hairs, and you generally lose roughly 100 of them each day. But what’s normal, and what’s not? Here’s what’s really going on, and what you can do about it.What Gives?Let’s face it: When it comes to physical changes, hair thinning is alarming, and hair loss? Well, that’s just downright devastating. It’s said to be one of the most personally distressing side effects of chemotherapy, and anyone who’s lost a clump of hair can relate to the accompanying feeling of shock and powerlessness.Psychologically, it’s a world apart from other so-called beauty “problems” like peeling nails or even breakouts, but just like wrinkles, hair simply tends to thin with age. Another common complaint is that the hair seems to simply stop growing, which is totally related. “It can also just be growing slower because [with age], the growth cycles become shorter,” says Dr. Bernstein.MORE: Preventing Chemo Hair LossHere’s the deal: Experts call age-onset thinning “miniaturization,” which refers to a progressive decrease of the hair shaft’s diameter and length. This happens at least in part because of androgens like dihydrotestosterone (or DHT), a derivative of the male hormone testosterone that causes hair follicles to literally shrink in diameter. This type of hair thinning is referred to as androgenic alopecia, and it occurs in an equal pattern all over the scalp. And if this sounds bad, consider yourselves lucky ladies, because for men (and some women), this condition usually manifests as more distinct patterns or “patches” of baldness, which tends to be way more noticeable.This hormonal connection is also one way that thinning hair can be more complicated to diagnose in women. Pregnancy, ovarian cysts, medications, emotional or physical shock, and birth control pills can affect hormone levels. “With women, there can be underlying causes,” says Bernstein. “You have to check for medical problems. For example, polycystic ovarian disease can exacerbate androgens and manifest as thinning, in which case you could treat the condition with an androgen blocker like spironolactone.”Heredity also plays a role in hair thinning and loss for both sexes. Ever heard the idea that if baldness runs in the men on your mothers’ side, a male spawn is likely to go bald too? Here’s a surprising update on that old wives’ tale: Dr. Bernstein asserts that baldness on either side of family can be indicative for genetic hair loss whether you’re a male or a female.RESEARCH: Hair Loss Can Signal Polycystic Ovary SyndromeIf you’ve ever noticed an alarming amount of hair—we’re talking about clumps—in your drain or on a hairbrush, think back a few months. That’s because this type of loss, called telogen effluvium, is caused when a trauma triggers the hair in growing phase to shift to shedding phase, usually about six weeks to three months after the event. A “trauma” can be defined as a major surgery, childbirth, or yes, a total stress freakout. While there are cases of this being a chronic disorder, luckily, the shedding phase is usually reversible.There are many other, less common types of hair loss (consult Dr. Bernstein’s super educational site, which offers extensive details) that can be diagnosed by a doc who can administer a “pull test” in order to examine factors such as the diameter of the follicle and what growth stage individual strands are in.What Helps, What Doesn’tLately, it seems a few members of the beauty industry have woken up and decided to start marketing anti-hair loss and anti-thinning products to women. But buyer beware: According to Dr. Bernstein, there’s simply no scientific evidence that any of these trendy new ingredients and herbal concoctions work. And prescription Propecia, also known as finasteride, which helps to lower DHT levels in men, “is not FDA-approved for women,” he says. “Some doctors use it, but there’s some indication that it points to breast problems, so I don’t recommend it.” A two percent minoxidil product, known over-the-counter as Rogaine, can help, but consistency is key: “It has to be used regularly; at least once a day, if not twice.”In more extreme cases, some women are candidates for Follicular Unit Extraction (FUE) Hair Transplants, a procedure by which hair is removed directly from the donor region of the scalp and grafted on to thin or bald spots. The latest technology? Because the implant process is so precise, a new device utilizes an image-guided robotic arm to get the job done.MORE: Hair Loss Linked to Marital StatusPerhaps more importantly, here’s what not to do if you’re looking to prevent hair loss or don’t want to make a bad sitch worse. While the logical step may seem to be adding hair extensions, unless they’re clip-in and you religiously take them out in the evenings, they’ll only damage hair and even cause more thinning and loss via aggressive rubbing and pulling, which is also referred to as traction alopecia. (For this reason, you also want to avoid tight ponytails, headbands, cornrows, and any hairstyle or accessory that can pull strands against the scalp.) Instead, Dr. Bernstein recommends superficial thickening via Toppik, a readily-available cosmetic keratin fiber that binds to the scalp and hair when you shake it onto thinning areas and makes it appear more full.And an even simpler solution? Change your part and lighten your hair. “Honestly, I tell my patients that grooming can take [them] a long way,” says Bernstein. While simply shifting a part works for obvious reasons, he points out that color-wise, “people tend to go darker… they think this will mask the problem, but it only emphasizes it. Light reflects more from light, so a lighter hair color provides less contrast between the hair and the scalp.” Additionally, a light perm or wave will give hair more body and make it look thicker, and frequent haircuts will help prevent breakage.As for maintaining the hair you’ve got, don’t neglect the “root of the problem,” so to speak, your scalp. “A healthy scalp is as important for healthy hair as healthy gums are for healthy teeth,” says David Kingsley, Ph.D., a trichologist and author of the book, The Hair-Loss Cure: A Self-Help Guide. While it’s rare for scalp issues to cause thinning or loss, conditions like oiliness or dryness can totally affect the way hair looks. For example, “a greasy scalp will make the hair look limp and thin,” he points out. He recommends making dietary changes: reduce dairy and fatty foods, as these can cause more flaking, and get tested for iron deficiency. (He also makes a scalp mask and scalp therapy for hair loss.)Finally, as hair thins, it tends to break more easily as well. “The coating that holds in water becomes drier and more brittle,” says Dr. Bernstein, so be sure to condition well to keep strands hydrated and healthy.After all, you moisturize your face to plump away the look of those aforementioned wrinkles, right?MORE: Sparse Brows? Try This.