Sometimes, adenomyosis is silent — causing no signs or symptoms — or only mildly uncomfortable. In other cases, adenomyosis may cause:
- Heavy or prolonged menstrual bleeding
- Severe cramping or sharp, knife-like pelvic pain during menstruation (dysmenorrhea)
- Menstrual cramps that last throughout your period and worsen as you get older
- Pain during intercourse
- Bleeding between periods
- Passing blood clots during your period
Your uterus may double or triple in size. Although you might not know if your uterus is enlarged, you may notice that your lower abdomen seems bigger or feels tender.
When to see a doctor
If you experience any signs or symptoms of adenomyosis, such as prolonged, heavy bleeding during your periods or severe cramping, and they interfere with regular activities, make an appointment to see your doctor.
The cause of adenomyosis isn't known. Expert theories about a possible cause include:
- Invasive tissue growth. Some experts believe that adenomyosis results from the direct invasion of endometrial cells from the surface of the uterus into the muscle that forms the uterine walls. Uterine incisions made during an operation such as a cesarean section (C-section) may promote the direct invasion of the endometrial cells into the wall of the uterus.
- Developmental origins. Other experts speculate that adenomyosis originates within the uterine muscle from endometrial tissue deposited there when the uterus first formed in the female fetus.
- Uterine inflammation related to childbirth. Another theory suggests a link between adenomyosis and childbirth. An inflammation of the uterine lining during the postpartum period might cause a break in the normal boundary of cells that line the uterus.
- Stem cell origins. A recent theory proposes that bone marrow stem cells may invade the uterine muscle, causing adenomyosis.
Regardless of how adenomyosis develops, its growth depends on the circulating estrogen in a woman's body. When estrogen production decreases at menopause, adenomyosis eventually goes away.
Risk factors for adenomyosis include:
- Prior uterine surgery, such as a C-section or fibroid removal
- Middle age
Most cases of adenomyosis, which depends on estrogen, are found in women in their 40s and 50s, with a low incidence after menopause. Finding adenomyosis in middle-aged women could relate to longer exposure to estrogen compared with that of younger women.
Although not harmful, the pain and excessive bleeding associated with adenomyosis can have a negative effect on your lifestyle. You may find yourself avoiding activities that you previously enjoyed because you have no idea when or where you might start bleeding. Painful periods can cause you to miss work or school and can strain relationships. Recurring pain can lead to depression, irritability, anxiety, anger and feelings of helplessness. That's why it's important to seek medical evaluation if you suspect you may have adenomyosis.
If you experience prolonged, heavy bleeding, chronic anemia may result.