What causes a chocolate cyst?

The name describes the thick, dark fluid inside the cyst; it does not refer to food or diet. An endometrioma is linked to endometriosis rather than the common functional cysts that can appear during ovulation.

Endometriosis-like tissue can attach to or grow into the ovary. It responds to hormonal changes and bleeds, but the blood cannot leave the ovary normally. Repeated accumulation creates a cyst filled with altered blood. One or both ovaries may be involved, and surrounding inflammation can contribute to scar tissue within the pelvis.

Ovarian endometriomas can present with painful periods, deep pain during sex, ongoing pelvic pain, or difficulty becoming pregnant. Some cause few symptoms and are found during imaging for another reason. Symptoms cannot determine the cyst's size or confirm its identity.

Book a gynaecology review for persistent pelvic pain, increasingly painful periods, pain during sex, or an ovarian cyst seen on a scan. Ultrasound commonly helps describe the cyst, while your symptoms, examination, pregnancy plans, and previous scans guide management. Options can include symptom control, hormonal treatment, monitoring, or surgery; treatment is individual because ovarian surgery may affect healthy ovarian tissue.

Seek urgent medical help for sudden severe pelvic pain, especially with vomiting, faintness, fever, a swollen abdomen, or feeling very unwell. These features can occur when an ovarian cyst ruptures, bleeds, or the ovary twists. New pelvic pain with a positive pregnancy test also requires prompt assessment.

Ask what features support an endometrioma diagnosis, whether repeat imaging is appropriate, and how each option may affect pain and fertility plans. If surgery is proposed, ask why it is recommended now, what procedure is planned, and how ovarian tissue will be protected.