Adenomyosis or endometriosis is a condition that occurs when the tissue that normally lines the uterus, called the endometrial tissue, grows into the muscular wall of the uterus. Although it is displaced, the endometrial tissue continues to perform its usual functions as in each menstrual cycle (thickening, breaking down and bleeding), which can cause an enlarged uterus and painful periods.

The exact cause of adenomyosis is not clear; however, the condition ceases to exist after menopause. There are treatments to ease the discomfort of the symptoms but the only cure is a hysterectomy. Most symptoms begin in the late childbearing years or after having children.

Symptoms

Adenomyosis may not present any signs or symptoms at all but on the other hand, it may cause symptoms such as:

• Painful, heavy and prolonged periods
• Severe or sharp cramping during menstruation (dysmenorrhea)
• Menstrual cramps during the entire period of menstruation
• Painful intercourse
• Blood clots passed through the period
• Difficulty in getting pregnant
• Enlarged or tender uterus

Other symptoms that occur less frequently include:

• Discomfort during urinating
• Rectal bleeding or blood in the stool
• Coughing blood (this happens in rare cases when the endometrial tissue develops in the lungs)
• Long-term exhaustion

Causes

The specific cause of adenomyosis is unknown; however, there are a few theories explaining the possible causes of the condition:

• Invasive tissue growth – Experts believe that endometriosis mainly occurs from the direct invasion of endometrial cells from the uterus into the muscle of the uterine walls. The same happens with retrograde menstruation where the endometrium flows backwards through the fallopian tubes into the abdomen where the endometrial tissue embeds onto the organs and starts growing. Uterine incisions such as a C-section make it more possible for the endometrial cells to invade the uterine walls or other organs.
• Developmental genesis – It is also possible that adenomyosis originates within the uterine muscle when the uterus first forms in the fetus because of the endometrial tissue that is accumulated there. Moreover, some experts believe that the condition is hereditary through family genetics.
• Uterine inflammation after childbirth – Adenomyosis is often associated with childbirth. The postpartum period could spark an inflammation of the uterine wall that may cause endometrial cells to break out of the boundary of the uterus. This may also allow the endometrial cells to spread through the bloodstream or the lymphatic system and end up in other organs.
• Stem cells – A more recent theory suggests that stem cells from the bone marrow may invade the uterine muscle and cause adenomyosis.
  On the other hand, the ability of some adult cells to change according to the environment may allow them to transform into endometrial cells during menstruation. This process is called metaplasia.

The development and growth of adenomyosis depends on the estrogen present in a woman’s body. Therefore, during menopause estrogen production diminishes and thus the adenomyosis disappears.

Complications

Adenomyosis may cause great discomfort and various complications ranging from chronic anemia due to prolonged or heavy bleeding during periods to recurring pain leading to depression, irritability and anxiety as well as more serious complications such as subfertility or infertility and adhesions or ovarian cysts.

Fertility issues – There is a possibility that endometriosis could damage the ovaries or fallopian tubes causing fertility problems or difficulties getting pregnant. However, most women with mild endometriosis still have the ability to get pregnant without treatment.

Visible endometriosis tissue can be removed surgically although that does not increase the fertility in women suffering from the condition.

Adhesions and ovarian cysts – Adhesions are formations of ‘sticky’ areas of endometriosis tissue that can fuse organs together while ovarian cysts are fluid-filled cysts that can appear when the endometriosis tissue is near the ovaries. The ovarian cysts, otherwise known as endometriomas can grow large in size and become painful.

Both the adhesions and endometriomas can be surgically removed but may recur if adenomyosis returns.

Risk factors

The risk factors for adenomyosis include:

• Uterine surgery prior to the condition such as a C-section or fibroid removal
• Childbirth
• Middle age (due to the longer exposure to estrogen)