An ovarian cyst is a fluid-filled or semi-solid sac that forms on or within one of the ovaries. These structures are common, and most individuals with ovaries will develop one at some point, often without knowing it. The ovaries are part of the reproductive system and produce eggs and reproductive hormones.
While most ovarian cysts are harmless and disappear naturally, a delayed or missed menstrual period can sometimes occur. This article explores how certain types of cysts can interfere with the hormonal timing required for a regular period.
Understanding Normal Ovarian Function
The ovaries orchestrate the entire menstrual cycle through the coordinated release of hormones. The first half of the cycle, known as the follicular phase, begins with the start of menstruation and involves the maturation of a follicle, which is a fluid-filled sac containing an egg. As the follicle grows, it produces increasing amounts of estrogen, which signals the uterine lining to thicken in preparation for a potential pregnancy.
The peak in estrogen ultimately triggers the release of a luteinizing hormone surge, leading to ovulation, where the mature egg is released from the ovary. Following ovulation, the second half of the cycle, the luteal phase, begins as the remnants of the ruptured follicle transform into a structure called the corpus luteum.
The corpus luteum produces progesterone, the hormone that stabilizes the thickened uterine lining. Progesterone ensures the uterus is receptive to a fertilized egg. If pregnancy does not occur, the corpus luteum naturally degrades after about 14 days, causing progesterone levels to plummet. This sharp drop in progesterone signals the uterine lining to shed, resulting in the start of the menstrual period.
The Direct Link Between Cysts and Cycle Disruption
Yes, certain ovarian cysts can directly cause a period to be missed or significantly delayed by interfering with the body’s hormonal signals. The cysts most commonly involved in cycle disruption are known as functional cysts, which arise directly from the normal process of the menstrual cycle. These functional cysts include follicular cysts and corpus luteum cysts.
A follicular cyst forms when the dominant follicle fails to rupture and release the egg during ovulation. Instead of releasing the egg, the follicle continues to grow and remain on the ovary, continuing to produce estrogen. The persistent estrogen production prevents the body from recognizing the cycle has ended, which can delay the signal for the uterine lining to shed, resulting in a late period.
Another mechanism involves a persistent corpus luteum cyst, which forms after ovulation has occurred. If the corpus luteum does not degrade as it should, it continues to produce progesterone beyond the usual 14-day lifespan. This sustained high level of progesterone maintains the uterine lining, essentially prolonging the luteal phase and preventing the period from starting on time. The period remains “missed” until the cyst finally involutes, or shrinks, and the progesterone level drops.
The duration of the delay can vary widely, from a few days to several weeks, depending on how long the cyst remains hormonally active. This is distinct from cysts associated with conditions like Polycystic Ovary Syndrome (PCOS), where irregular periods are caused by a broader, chronic hormonal imbalance that prevents ovulation entirely.
Accompanying Symptoms and Medical Guidance
While a missed period can be the first sign of a cyst, several other localized symptoms may occur concurrently. Many cysts are asymptomatic, but larger or complex cysts can cause pressure, a feeling of fullness, or bloating in the abdomen. Pelvic pain is also a common symptom, which can manifest as a dull ache or a sharp, intermittent pain, often localized to the side of the ovary containing the cyst.
Some people experience pain during sexual intercourse (dyspareunia) or discomfort during bowel movements due to the physical pressure the cyst exerts on nearby organs. These symptoms may fluctuate based on the cyst’s size and position within the pelvis. The presence of these physical symptoms alongside a change in the menstrual cycle warrants evaluation by a healthcare provider.
It is important to seek immediate medical attention if a person experiences sudden, severe pelvic or abdominal pain. This intense pain, especially if accompanied by fever, vomiting, dizziness, or lightheadedness, may indicate a complication such as ovarian torsion or a ruptured cyst. Ovarian torsion occurs when the ovary twists on its supporting ligaments, cutting off its blood supply, while a rupture can lead to internal bleeding.
A healthcare provider can use a pelvic ultrasound to confirm the presence, size, and type of ovarian cyst. Management often involves observation, as most functional cysts resolve on their own within one to three menstrual cycles. Tracking cycle changes and associated symptoms remains an important first step in determining the need for professional medical intervention.