An enlarged ovary is one larger than its typical size (2.5 to 5 cm for reproductive-age women). It prompts medical evaluation, but is not a diagnosis. Ovarian enlargement stems from various reasons, many benign and self-resolving. Some, however, require medical attention or monitoring. It indicates various conditions affecting ovarian health.
Ovarian Cysts
Ovarian cysts are fluid-filled sacs and a common cause of ovarian enlargement. Most cysts are harmless, often resolve on their own, and cause no symptoms. Sizes range from a few to over 30 centimeters.
Functional cysts are the most frequent type. A follicular cyst develops when a follicle fails to release its egg and continues to grow. A corpus luteum cyst forms after egg release, when the sac reseals and fills with fluid. These functional cysts are temporary, resolving within one to three menstrual cycles.
Pathological cysts are less common. Endometriomas, called “chocolate cysts,” are filled with old menstrual blood and linked to endometriosis, where uterine-like tissue grows elsewhere. Dermoid cysts (teratomas) arise from reproductive cells and can contain tissues like hair, skin, or teeth. Cystadenomas form on the ovarian surface and can contain watery or mucous fluid, growing large. These pathological cysts can contribute to ovarian enlargement and may cause pelvic pain or pressure.
Hormonal Imbalances
Hormonal imbalances can impact ovarian size, with Polycystic Ovary Syndrome (PCOS) being a primary example. PCOS is a common endocrine disorder characterized by an imbalance of hormones, including elevated androgens, insulin resistance, and disrupted estrogen and progesterone ratios. This disruption can lead to irregular or absent ovulation.
In PCOS, instead of releasing a mature egg, follicles develop into many small, fluid-filled sacs around the edge of the ovary. These are often mistakenly called “cysts,” but are actually underdeveloped follicles. Numerous small follicles (typically up to 8mm) contribute to ovarian enlargement.
Excess androgen levels can lead to irregular periods, excessive hair growth (hirsutism), acne, and weight gain. Insulin resistance, where cells don’t respond effectively to insulin, often accompanies PCOS and can further increase androgen production, worsening symptoms.
Inflammation and Infection
Inflammation and infection can cause ovarian enlargement, especially with Pelvic Inflammatory Disease (PID). PID is an infection of the female reproductive organs, often caused by sexually transmitted bacteria (e.g., chlamydia, gonorrhea). This infection can spread from the vagina and cervix to the uterus, fallopian tubes, and ovaries.
When the infection reaches the ovaries, it causes inflammation, known as oophoritis. This inflammation can swell and enlarge one or both ovaries. While sometimes asymptomatic, PID and oophoritis can cause lower abdominal pain, abnormal vaginal discharge, heavier or irregular menstrual bleeding, and pain during intercourse or urination.
Untreated, inflammation and infection can lead to complications like abscesses, chronic pelvic pain, and fertility issues due to scarring or organ damage. Early diagnosis and treatment with antibiotics are important to prevent these long-term effects.
Other Growths and Conditions
Ovarian enlargement can result from other growths and conditions, some requiring immediate medical attention. Benign ovarian tumors (non-cancerous growths) can enlarge the ovary. These tumors, like fibromas or certain cystadenomas, grow slowly and do not spread. While often asymptomatic, larger benign tumors can cause pelvic pain, pressure, or fullness.
Ovarian enlargement can signal malignant ovarian tumors (cancerous growths). While less common than benign causes, ovarian cancer requires medical evaluation. Originating from different ovarian cell types, these tumors may present with symptoms like bloating, discomfort, changes in bowel habits, or frequent urination.
Endometriosis can also lead to overall ovarian enlargement or adhesions. It involves endometrial-like tissue growing outside the uterus, attaching to ovaries and surrounding structures. This tissue growth can cause inflammation and scarring, making the ovary appear larger or fixed by adhesions.
Ovarian torsion is an acute, serious condition where an ovary twists on its supporting ligaments. This twisting cuts off blood supply, leading to rapid swelling and pain. Ovarian torsion presents with sudden, intense pelvic pain, often accompanied by nausea and vomiting. It is a medical emergency; prolonged lack of blood flow can cause tissue damage or even loss of the ovary, requiring prompt surgical intervention.