Adenomyosis can vary widely in the type and severity of symptoms that it causes, ranging from being entirely asymptomatic 33% of the time to being a severe and debilitating condition in some cases. Women with adenomyosis typically first report symptoms when they are between 40 and 50, but symptoms can occur in younger women.

Symptoms and the estimated percent affected may include:

- Chronic pelvic pain (77%)

- Heavy menstrual bleeding (40-60%), which is more common with in women with deeper adenomyosis. Blood loss may be significant enough to cause anemia, with associated symptoms of fatigue, dizziness, and moodiness.

- Abnormal uterine bleeding

- Painful cramping menstruation (15-30%)

- Painful vaginal intercourse (7%)

- A 'bearing' down feeling

- Pressure on bladder

- Dragging sensation down thighs and legs

Clinical signs of adenomyosis may include:

- Uterine enlargement (30%), which in turn can lead to symptoms of pelvic fullness.

- Tender uterus

- Infertility or sub-fertility (11-12%) - In addition, adenomyosis is associated with an increased incidence of preterm labour and premature rupture of membranes.

Women with adenomyosis are also more likely to have other uterine conditions, including:

- Uterine fibroids (50%)

- Endometriosis (11%)

- Endometrial polyp (7%)

Adenomyosis is a gynecologic medical condition characterized by the abnormal presence of endometrial tissue (the inner lining of the uterus) within the myometrium (the thick, muscular layer of the uterus). In contrast, when endometrial tissue is present entirely outside the uterus, it represents a similar but distinct medical condition called endometriosis. The two conditions are found together in many cases, but often occur independently. Before being recognized as its own condition, adenomyosis used to be called "endometriosis interna". Additionally, the less-commonly used term "adenomyometritis" is a more specific name for the condition, specifying involvement of the uterus.

The condition is typically found in women between the ages of 35 and 50 but can also be present in younger women. Patients with adenomyosis often present with painful and/or profuse menses (dysmenorrhea & menorrhagia, respectively). Other possible symptoms are pain during sexual intercourse, chronic pelvic pain and irritation of the urinary bladder.

In adenomyosis, "basal" endometrium penetrates into hyperplastic myometrial fibers. Therefore, unlike functional layer, basal layer does not undergo typical cyclic changes with menstrual cycle.

Adenomyosis may involve the uterus focally, creating an adenomyoma. With diffuse involvement, the uterus becomes bulky and heavier.

Pain and infertility are common symptoms, although 20-25% of women are asymptomatic.

A major symptom of endometriosis is recurring pelvic pain. The pain can range from mild to severe cramping or stabbing pain that occurs on both sides of the pelvis, in the lower back and rectal area, and even down the legs. The amount of pain a woman feels correlates weakly with the extent or stage (1 through 4) of endometriosis, with some women having little or no pain despite having extensive endometriosis or endometriosis with scarring, while other women may have severe pain even though they have only a few small areas of endometriosis. Symptoms of endometriosis-related pain may include:

- dysmenorrhea – painful, sometimes disabling cramps during the menstrual period; pain may get worse over time (progressive pain), also lower back pains linked to the pelvis

- chronic pelvic pain – typically accompanied by lower back pain or abdominal pain

- dyspareunia – painful sex

- dysuria – urinary urgency, frequency, and sometimes painful voiding

Compared with women with superficial endometriosis, those with deep disease appear to be more likely to report shooting rectal pain and a sense of their insides being pulled down. Individual pain areas and pain intensity appear to be unrelated to the surgical diagnosis, and the area of pain unrelated to area of endometriosis.

There are multiple causes of pain. Endometriosis lesions react to hormonal stimulation and may "bleed" at the time of menstruation. The blood accumulates locally if it is not cleared shortly by the immune, circulatory, and lymphatic system. This may further lead to swelling, which triggers inflammation with the activation of cytokines, which results in pain. Another source of pain is the organ dislocation that arises from adhesion binding internal organs to each other. The ovaries, the uterus, the oviducts, the peritoneum, and the bladder can be bound together. Pain triggered in this way can last throughout the menstrual cycle, not just during menstrual periods.

Also, endometriotic lesions can develop their own nerve supply, thereby creating a direct and two-way interaction between lesions and the central nervous system, potentially producing a variety of individual differences in pain that can, in some women, become independent of the disease itself. Nerve fibres and blood vessels are thought to grow into endometriosis lesions by a process known as Neuroangiogenesis.

Some women with uterine fibroids do not have symptoms. Abdominal pain, anemia and increased bleeding can indicate the presence of fibroids. There may also be pain during intercourse, depending on the location of the fibroid. During pregnancy, they may also be the cause of miscarriage, bleeding, premature labor, or interference with the position of the fetus. A uterine fibroid can cause rectal pressure. The abdomen can grow larger mimicking the appearance of pregnancy. Some large fibroids can extend out through the cervix and vagina.

While fibroids are common, they are not a typical cause for infertility, accounting for about 3% of reasons why a woman may not be able to have a child. The majority of women with uterine fibroids will have normal pregnancy outcomes. In cases of intercurrent uterine fibroids in infertility, a fibroid is typically located in a submucosal position and it is thought that this location may interfere with the function of the lining and the ability of the embryo to implant.

Fibroids that lead to heavy vaginal bleeding lead to anemia and iron deficiency. Due to pressure effects gastrointestinal problems such as constipation and bloatedness are possible. Compression of the ureter may lead to hydronephrosis. Fibroids may also present alongside endometriosis, which itself may cause infertility. Adenomyosis may be mistaken for or coexist with fibroids.

In very rare cases, malignant (cancerous) growths, leiomyosarcoma, of the myometrium can develop. In extremely rare cases uterine fibroids may present as part or early symptom of the hereditary leiomyomatosis and renal cell cancer syndrome.

Bleeding before the expected time of menarche could be a sign of precocious puberty. Other possible causes include the presence of a foreign body in the vagina, molestation, vaginal infection (vaginitis), and rarely, a tumor.

Most unusual bleeding or irregular bleeding (metrorrhagia) in premenopausal women is caused by changes in the hormonal balance of the body. These changes are not pathological. Exceptionally heavy bleeding during menstruation is termed "menorrhagia" or "hypermenorrhea", while light bleeding is called "hypomenorrhea". Women on hormonal contraceptives can experience breakthrough bleeding and/or withdrawal bleeding. Withdrawal bleeding occurs when a hormonal contraceptive or other hormonal intake is discontinued.

There are pathological causes of unusual vaginal bleeding as well. Dysfunctional uterine bleeding is a common cause of menorrhagia and irregular bleeding. It is due to a hormonal imbalance, and symptoms can be managed by use of hormonal contraception (although hormonal contraception does not treat the underlying cause of the imbalance). If it is due to polycystic ovary syndrome, weight loss may help, and infertility may respond to clomifene citrate. Uterine fibroids (leiomyoma) are benign tumors of the uterus that cause bleeding and pelvic pain in approximately 30% of affected women. Adenomyosis, a condition in which the endometrial glands grow into the uterine muscle, can cause dysmenorrhea and menorrhagia. Cervical cancer may occur at premenopausal age, and often presents with "contact bleeding" (e.g. after sexual intercourse). Uterine cancer leads to irregular and often prolonged bleeding. In recently pregnant women who have delivered or who have had a miscarriage, vaginal bleeding may be a sign of endometritis or retained products of conception.

The main symptom of dysmenorrhea is pain concentrated in the lower abdomen or pelvis. It is also commonly felt in the right or left side of the abdomen. It may radiate to the thighs and lower back.

Symptoms often co-occurring with menstrual pain include nausea and vomiting, diarrhea or constipation, headache, dizziness, disorientation, hypersensitivity to sound, light, smell and touch, fainting, and fatigue. Symptoms of dysmenorrhea often begin immediately after ovulation and can last until the end of menstruation. This is because dysmenorrhea is often associated with changes in hormonal levels in the body that occur with ovulation. The use of certain types of birth control pills can prevent the symptoms of dysmenorrhea because they stop ovulation from occurring.

Uterine hyperplasia, or enlarged uterus, is a medical symptom in which the volume and size of the uterus in a female is abnormally high. It can be a symptom of medical conditions such as adenomyosis, uterine fibroids, ovarian cysts, and endometrial cancer.

Dysmenorrhea, also known as painful periods, or menstrual cramps, is pain during menstruation. Its usual onset occurs around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in the pelvis or lower abdomen. Other symptoms may include back pain, diarrhea, or nausea.

In young women painful periods often occur without an underlying problem. In older women it is more often due to an underlying issues such as uterine fibroids, adenomyosis, or endometriosis. It is more common among those with heavy periods, irregular periods, whose periods started before twelve years of age, or who have a low body weight. A pelvic exam in those who are sexually active and ultrasound may be useful to help in diagnosis. Conditions that should be ruled out include ectopic pregnancy, pelvic inflammatory disease, interstitial cystitis, and chronic pelvic pain.

Dysmenorrhea occurs less often in those who exercise regularly and those who have children early in life. Treatment may include the use of a heating pad. Medications that may help include NSAIDs such as ibuprofen, hormonal birth control, and the IUD with progestogen. Taking vitamin B or magnesium may help. Evidence for yoga, acupuncture, and massage is insufficient. Surgery may be useful if certain underlying problems are present.

Dysmenorrhea is estimated to occur in 20% to 90% of women of reproductive age. It is the most common menstrual disorder. Typically it starts within a year of the first menstrual period. When there is no underlying cause often the pain improves with age or following having a child.

A boggy uterus is a finding upon physical examination where the uterus is more flaccid than would be expected.

It can be associated with uterine atony.

It may also be associated with adenomyosis.

Adenomyoma is a tumor ("-oma") including components derived from glands ("adeno-") and muscle ("-my-"). It is a type of complex and mixed tumor.

In obstetrics and gynecology contexts, it is a form of adenomyosis that forms a mass or growth around the tissue of the inner uterus.

Most cases of adenomyosis are non-symptomatic. However, it may present with dysmenorrhea and pelvic pain. In the case of juvenile cystic adenomyoma, laparoscopic enucleation results in a statistically and clinically significant reduction in dysmenorrhea, ease in any chronic pelvic pain, and low risk of recurrence.

An estrogen-dependent condition, disease, disorder, or syndrome, is a medical condition that is, in part or full, dependent on, or is sensitive to, the presence of estrogenic activity in the body.

Known estrogen-dependent conditions include mastodynia (breast pain/tenderness), breast fibroids, mammoplasia (breast enlargement), macromastia (breast hypertrophy), gynecomastia, breast cancer, precocious puberty in girls, melasma, menorrhagia, endometriosis, endometrial hyperplasia, adenomyosis, uterine fibroids, uterine cancers (e.g., endometrial cancer), ovarian cancer, and hyperestrogenism in males such as in certain conditions like cirrhosis and Klinefelter's syndrome.

Such conditions may be treated with drugs with antiestrogen actions, including selective estrogen receptor modulators (SERMs) such as tamoxifen and clomifene, estrogen receptor antagonists such as fulvestrant, aromatase inhibitors such as anastrozole and exemestane, gonadotropin-releasing hormone (GnRH) analogues such as leuprolide and cetrorelix, and/or other antigonadotropins such as danazol, gestrinone, megestrol acetate, and medroxyprogesterone acetate.