At age 18, John figured out he was balding from a photo on Facebook.

Growing up, John — now a 28-year-old San Francisco public relations professional who asked that we withhold his real name — prided himself on his luscious locks. “I had always had a thick, full head of hair — I’m of Middle Eastern/Jewish ancestry,” he says. “That was closely associated with my identity.” But as a freshman in college, he discovered that he was losing his hair when a friend posted a photo of him on Facebook. “I was kind of stunned. It was really brutal,” he says, noting it was the thinning hair around his temples that gave it away. “I just assumed [balding] was something that magically happened at 45.”

For Mabel it was a clogged shower drain that alerted her to the problem. Already stressed by the pressures of college (she was a premed major and had picked up a minor), and feeling homesick for her family in Hawaii, Mabel, then 19, says the hair loss was devastating. “I thought, oh my god, am I really losing my hair,” she says. “It was crushing. Hair is a very feminine thing.”

Experts say they’re seeing more people like John and Mabel: men and women as young as 18 who are freaking out about going bald. San Francisco dermatologist Andrea Hui says balding millennials are coming to her more than ever, asking her for everything from natural supplements like Nutrafol to more invasive procedures like PRP, which involves injecting your own plasma into your scalp. New York City stylist Angelo David has seen a “tremendous” number of young and balding clients too: “The new hair extension story is no longer short to long but thin to thick,” he says. “People want full and voluminous hair.” One of his most recent clients, in fact, was a college student just shy of her 20th birthday who had severe hair loss. “She was devastated,” he says, spending roughly $4000 on a customized, couture wig to cover up the issue.

One big reason for the follicle freakout? High stress, say both Hui and David. Indeed, millennials are more stressed out that any other generation, according to research from the American Psychological Association. And that stress can lead to hair loss, research shows. There’s a condition called telogen effluvium, which happens when “significant stress pushes large numbers of hair follicles into a resting phase” and then hair falls out, and one called alopecia areata, in which your immune system attacks the hair follicles, which can be exacerbated by stress. There’s also a disorder called trichotillomania, in which stressed-out people feel an irresistible urge to pull their hair out.

Of course, hair loss is still a bigger problem for older people than young ones — Dr. Arielle Levitan, the author of “The Vitamin Solution,” notes that while she does have some patients with hair loss in their 20s, there are far more in the older demographics. And it could be that the incidence of hair loss in young people isn’t greater now than in the past, but merely that doctors and stylists are hearing about it more because millennials are more proactive about seeking help.

Whatever the reasons for the hair loss — and Hui notes that genetics and extreme diets are other big reasons she’s seeing for it — one thing is clear: Millennials aren’t going to stand for it. After visiting a doctor and trying Propecia — which has side effects that include possible impotence — for a month, John simply shaved all his hair off. “Now I’m completely bald,” he says. “And I haven’t worried about it [balding] since.”