“Women know they’re losing hair long before it’s noticeable to other people,” says Michael Reed, a professor of clinical dermatology at New York University Medical Center. If you see your scalp through the front of your hair, a widening of your part, a smaller ponytail, or clumps of hair on your pillow, here are some factors that could be at the root of it.

Cause: A family history of hair loss.

By far, the most common form of hair loss in women is female-pattern hair loss, which is often genetic and can be passed down from either side of the family. The area behind the hairline and on top of the head thins out, or hair loss is diffuse throughout the scalp. “Women generally don’t need to worry about going bald in the same way as men do,” says Cherie M. Ditre, an assistant professor of dermatology at the University of Pennsylvania School of Medicine.

Remedy: The only medication approved by the Food and Drug Administration (FDA) to help regrow hair in women is Rogaine, an over-the-counter topical minoxidil. “It helps slow down or stops the progression of the hair loss, and you may get a little regrowth,” says Jeffrey Epstein, a hair-transplant surgeon and the director of the Women’s Center for Hair Loss and the Foundation for Hair Restoration, in Miami and New York. The hitch: You have to keep using it to reap the benefits. “Once you stop, the hair immediately begins shedding off,” says Alex Khadavi, an associate professor of dermatology at the University of Southern California. Rogaine may cause scalp irritation and redness. Also, pregnant and nursing women should consult their doctors before using it.

Cause: A change of seasons.

Each strand of hair has a growth phase of several years and enters a resting phase of three to four months before shedding. In the winter and summer, slightly more hair strands are in that resting phase, so you’ll see more hair shedding a few months later in the spring and fall, says Doris J. Day, a clinical assistant professor of dermatology at New York University Medical Center. At that point, the follicle from which the strand fell begins to sprout new hair.

Remedy: Wait it out — and be assured that different hairs are in different phases of the growth cycle at any given time, which is why you don’t go bald every few years.