Spotting between periods can be caused by a variety of reproductive health issues. In some cases, spotting may be a symptom of endometriosis.

What Is Spotting?

Most women have a menstrual cycle of approximately 28 days, in which menstruation (bleeding, or your period) occurs for about five days. Spotting, also called intermenstrual bleeding, is light bleeding that happens in between your periods.

Spotting may be common, but it is also considered abnormal, so it’s often important to determine the cause.

What Is Endometriosis?

Endometriosis is a condition when the endometrium (the tissue that is supposed to line the uterus) grows outside of the uterus in the pelvic region. During the menstrual cycle, normal uterine endometrial tissue thickens, breaks down, and bleeds as a period. Endometrial lesions (growths of endometrial tissue outside of the uterus) also follow the menstrual cycle, shedding into the pelvic cavity when the person is having their period. The tissue that sheds outside of the uterus cannot escape the body and can cause painful scar tissue to form in the pelvic cavity.

Symptoms of endometriosis include heavy periods, severe pelvic pain, lower back pain, pain during intercourse, infertility, and painful bowel movements. Dysmenorrhea (severely painful periods) is a common symptom of endometriosis.

Is Spotting a Symptom of Endometriosis?

Spotting may be a common symptom of endometriosis. As one MyEndometriosisTeam member commented, “I have been spotting before and after my regular menstrual cycle every month since February. It has been accompanied with severe pelvic pain recently.”

This member’s experience is backed by research. A study of 80 women who had fertility issues and who experienced more than two days of premenstrual spotting found that 89 percent of those women had endometriosis. These researchers concluded that premenstrual spotting of more than two days may be a better predictor of endometriosis than painful periods or pain during intercourse.

What Are Other Known Causes of Spotting?

Spotting may be due to endometriosis, but there are many other reasons why some spotting occurs between menstrual cycles.

Birth Control

Most hormonal contraceptives (birth control) can cause breakthrough bleeding or light spotting in between menstrual cycles. Breakthrough bleeding can be caused by any type of hormonal birth control methods, but low-dose birth control pills, hormonal intrauterine devices, and other implants are more likely to cause spotting or light bleeding in between periods.

MyEndometriosisTeam members on oral progesterone drugs such as Visanne (dienogest) and Norethindrone (norethisterone) — which shorten, lighten, or eliminate a period — frequently report brown spotting. “They told me when I started that after six months, it’s common to have irregular spotting,” one member shared.

Pregnancy or Implantation Bleeding

Up to 25 percent of pregnant women will experience some light bleeding or spotting one to two weeks after the egg implants into the uterus. The cervix will develop more blood vessels during pregnancy, which may lead to light bleeding or spotting after sex or a pelvic exam.

Ovulation

The ovulation phase is typically 14 days into a 28-day menstruation cycle. The sudden increase in the hormones estrogen and progesterone causes the ovaries to release an egg. This fluctuation in hormones may also cause slight bleeding. Less than 5 percent of women will have regular spotting during ovulation.

Perimenopause or Menopause

The perimenopause phase is a stage before menopause, which is when a woman has gone 12 months without a menstrual period. Many women experience lighter menstrual flows or spotting in between menstrual cycles as they reach the end of their reproductive age and get closer to menopause. Other symptoms of perimenopause include vaginal dryness and hot flashes.

Mild Trauma

Some women experience light bleeding after a pap smear, pelvic exam, or sex. One member wrote, “I sometimes had some spotting after a pap, especially if I got it the week before my period.”

Cancer

Some of the more serious causes of spotting include endometrial cancer and cervical cancer as well as some other types of cancer. Although the spotting is likely caused by something else (especially if you’re under 45), make sure to see your doctor about any new or unexpected bleeding as soon as possible so they can check it out.

Other Causes

There are many other potential causes of bleeding between your periods, including:

• Ectopic pregnancy
• Miscarriage
• Stress
• Improper use of birth control and other hormone fluctuations
• Blood thinner use

Consulting a Doctor

Spotting is a common symptom for women with endometriosis. However, it is important to report any changes in your menstrual flow, including heavy spotting, to your health care provider immediately. If you already know you have endometriosis, a change of medication can often reduce or eliminate spotting and endometriosis pain.

If you’re concerned that you may have endometriosis, talk to your doctor about running a diagnostic exam. This exam may involve a laparoscopy, which is a minor surgical procedure where a slim tube called a laparoscope is inserted in the abdomen and pelvic area. This procedure can be used to take a biopsy of tissue to help diagnose endometriosis or to remove small endometriosis lesions.

If you have endometriosis, your doctor will help determine the best treatment options and help you maintain a better quality of life.

Talk With Others Who Understand

MyEndometriosisTeam is the social network for people with endometriosis. On MyEndometriosisTeam, more than 120,000 members come together to ask questions, give advice, and share their stories with others who understand life with endometriosis.

If you have endometriosis, was abnormal vaginal bleeding an early sign? Share your experience in the comments below, or start a conversation by posting on MyEndometriosisTeam.