This article originally appeared on Health.com.
Most women cope with heavy periods, killer menstrual cramps, and painful sex once in a while. But for up to 10% of women of childbearing age, these symptoms signal something more serious: endometriosis.
Endometriosis is a condition in which endometrial tissue — the lining of the uterus — migrates outside the uterus and adheres to nearby body parts, such as the fallopian tubes, bladder, or bowels. Every month during the menstrual cycle, it becomes inflamed and swells. “Endometriosis is a war zone,” says Tamer Seckin, MD, founder and medical director of the Endometriosis Foundation of America (EFA) and author of The Doctor Will See You Now: Recognizing and Treating Endometriosis. “If it’s not treated, it’s a wound that never heals throughout the reproductive life of a woman.”
Problem is, doctors frequently mistake endometriosis for other conditions that can cause pelvic pain, such as irritable bowel syndrome (IBS), pelvic inflammatory disease, or even premenstrual syndrome (PMS). And although many women with endometriosis experience severe, debilitating symptoms, some have none at all.
If you’re experiencing these signs of endometriosis—severe or not—make an appointment with an endometriosis specialist.
Gut-wrenching cramping that doesn’t go away after popping a couple NSAIDs is one of the hallmark signs of endometriosis. The abdominal pains can begin a few days before your period and last beyond the first few days of your flow, says Dr. Seckin. The pain can be so debilitating that it takes you away from daily activity, he says.
With endometriosis, unrelenting pain isn’t the only thing your menstrual cycle brings. Excessive bleeding is another common endometriosis symptom. You may soak through your tampon or pad every hour or two throughout your period, and may see clumps of blood, Dr. Seckin says.
Your period shouldn’t be longer than six days, Dr. Seckin says. With endometriosis, periods can go on for over a week.
When renegade endometrial tissue that travels outside the uterus, it can stick to different organs and freeze them in place. The lack of flexibility can make sex very painful. “In early cases, intercourse just before your period is painful,” says Dr. Seckin. “In advanced cases, sex is painful all the time.” Arousal and orgasms both hurt—even during masturbation, he says.
Painful bowel movements and urination
Endometrial tissue can adhere to the bowels, making something as simple as going to the bathroom a wince-inducing experience. Bowel symptoms can vary from patient to patient, and may include constipation, diarrhea, intestinal cramping, nausea, rectal pain, and rectal bleeding.
Nausea and fatigue
Imagine your worst bout of PMS ever—you probably had a few days of feeling unusually tired, a little achy, and maybe even a little queasy. Now, amplify that hundredfold, and you have a better idea of what it’s like to deal with endometriosis around your period. Endometriosis can cause persistent nausea, vomiting, and exhaustion that’s worse around that time of the month.
Approximately 30 to 40% of women with endometriosis experience fertility issues, according to the EFA. In fact, many women don’t even realize they have endometriosis until they seek fertility treatment.