What Are the Causes of Midcycle Bleeding?

Menstruation is a process that occurs when the uterus sheds its lining in preparation for a new reproductive cycle. Normal menstruation occurs every 21 to 35 days, and can last for a few or several days, depending on the individual. Midcycle spotting is any bleeding that occurs outside of normal menstruation, and can indicate underlying gynecological conditions.

Uterine Fibroids

Uterine fibroids are noncancerous tumors that develop in the uterus 2. The exact cause of uterine fibroids is unknown, but estrogen imbalance is believed to be responsible, according to MedlinePlus 2. Uterine fibroids can range in size from microscopic to several pounds and usually develop in clusters 2. Small fibroids usually do not require immediate treatment and will be monitored for growth regularly. Large fibroids may be treated with hormone therapy or surgical removal of the individual fibroid or the entire uterus.


Endometriosis is a condition characterized by abnormal growth of the endometrium, which is the lining of the uterus that sheds during menstruation 3. In normal cases, the endometrium only grows inside the uterus. In those with endometriosis, the endometrium may grow on the fallopian tubes, ovaries or pelvic tissue 3. Even when the endometrium is located in abnormal places in the body, it still sheds as it would from the uterus. Some of the blood may exit the body, and some can become trapped and cause irritation and inflammation in surrounding areas. Symptoms of endometriosis include:

  • painful periods
  • pelvic pain
  • heavy periods
  • midcycle spotting
  • infertility
  • according to MayoClinic.com 3

Initial treatment attempts for endometriosis consist of medications and hormone therapy 3. In severe cases, surgery may be needed to remove the affected areas.


The cervix is the narrow end of the uterus that opens into the vagina. Cervicitis is the inflammation of the cervix. Cervicitis is usually caused by an infection, such as chlamydia or herpes, but can also be caused by an allergy or exposure to chemicals, according to the University of Maryland Medical Center 4. Symptoms of cervicitis include midcycle spotting, unusual vaginal discharge, pain during sexual intercourse, vaginal pain and pelvic pressure. Most cases of cervicitis can be easily treated. Treatment involves freezing of the cervix, burning of the cervix, hormone therapy or medications.