While small blood clots are normal during menstruation, people who have endometriosis can have larger than normal blood clots during their periods. Endometriosis is a disease in which the endometrium, the tissue that normally lines the uterus, grows outside of the uterus. This tissue can spread throughout the pelvis and grow on pelvic organs such as the ovaries and fallopian tubes.

During the menstrual cycle, normal endometrial tissue builds up, breaks down, and sheds. In people with endometriosis, the endometrial tissue growing outside the uterus also sheds, often leading to adhesions and scar tissue and causing severe pain and inflammation during the menstrual cycle.

Are Blood Clots a Common Symptom of Endometriosis?

Some individuals with endometriosis notice large blood clots during their periods, which can cause them additional pain and sometimes anxiety. One MyEndometriosisTeam member wrote, “I have had many golf ball-sized clots during my cycles.” Another member responded, “I’ve had some maybe larger than that. It scared the life out of me.”

These large blood clots can make it difficult to function normally. One member shared, “I would put on heavy overnight pads, wear a tampon, and still bleed through on my way to work! I was forced to quit my job.”

For some people with endometriosis, blood clots occur frequently. One member wrote, “I pass large clots every cycle.” Another member wrote, “At one point I thought I was freaking bleeding to death, but the doctor said it was normal [for] somebody who had endometriosis. The pain was unbelievable.”

A 2019 study of over 500 women showed that women with endometriosis have a tendency for increased blood clotting compared to women without endometriosis. While large blood clots are a common symptom of endometriosis, they can also be caused by other issues that may require medical attention.

When To Seek Medical Attention

Heavy menstrual bleeding, or menorrhagia, is a heavy period that lasts more than seven days, requires changing of a tampon or pad within two hours, or involves blood clots that are larger than a quarter. Some of the causes of menorrhagia include uterine polyps or fibroids, cervical or uterine cancer, or transition into menopause. Using a nonhormonal intrauterine device (IUD) can also increase menstrual flow and the incidence of blood clots. Increased blood loss can cause anemia, which can cause fatigue and other health issues.

While having heavy periods may be more common for people with endometriosis, it is important to seek medical attention when you notice any changes in your menstrual cycle — especially if you have blood clots larger than a quarter. A medical professional will be able to identify the reason for the blood clots.

Common Treatments for Heavy Menstrual Periods and Blood Clots

For people with endometriosis, doctors typically recommend over-the-counter pain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, to help reduce cramping and possibly reduce menstrual bleeding. It is important to consult a medical professional before starting a medication regimen, as NSAIDs can increase the risk of bleeding in some people.

Hormonal contraceptives like birth control pills or patches that have progestin (a synthetic form of progesterone) or a combination of estrogen and progestin can also help ease endometriosis symptoms. These contraceptives have been shown to reduce excessive menstrual bleeding and may help reduce the incidence of blood clots. Hormonal IUDs have also been shown to reduce heavy menstrual bleeding. A doctor will be able to recommend a hormonal drug therapy that is best for your specific needs.

One MyEndometriosisTeam member wrote, “The only way my pain and bleeding stopped was going [on] progesterone. I was bleeding 24/7 for over 1.5 years. Then I went on progesterone, and it all went away. Once in a while [I have] pain, but maybe every other month for one day.” Always consult a health care professional before beginning any type of treatment.

Your doctor may also recommend a surgery called laparoscopy, which is a minimally invasive surgical procedure performed in people with endometriosis to diagnose and remove endometriosis lesions. In laparoscopy, the doctor will make small incisions in the abdominal wall to insert a small camera and surgical tools. Then, they can examine the pelvic cavity and burn or cut away any endometriosis adhesions or implants.

Other treatments for endometriosis include diet changes, medications, and other surgeries.

Practical Tips for Dealing With Blood Clots

You should consult with a medical professional when you have blood clots larger than a quarter. Your doctor can help determine the cause of the blood clots and possible treatment options. Practical tips for managing larger blood clots or a heavy menstrual flow include:

• Wear both a heavy pad and tampon or menstrual cup during your menstrual cycle.
• Wear period underwear as backup leak protection.
• Carry extra period supplies and a change of clothes in case of leaks. Keep extra supplies and clothes handy, like at work or in your car.
• Wear dark clothing to hide any leaks.
• At night, sleep over a dark towel or waterproof pad.
• Use hydrogen peroxide to remove blood stains from clothing or sheets.
• Pay attention to where bathrooms are while you’re out, so you can get there quickly if you are passing a blood clot.

While period pain and blood clots are common symptoms of endometriosis, it’s important to consult a doctor if you notice a change in your menstrual flow — especially if you begin to have larger blood clots regularly.

Talk With Others Who Understand

MyEndometriosisTeam is the social network for women with endometriosis and their loved ones. On MyEndometriosisTeam, more than 119,000 members come together to ask questions, give advice, and share their stories with others who understand life with endometriosis.

Have you experienced blood clots with endometriosis? Do you have tips for managing them? Share your experience in the comments below, or start a conversation by posting on your Activities page.