Ovarian cysts are common, fluid-filled sacs that develop on or within the ovaries. Most women will experience one at some point, as these cysts often form as a normal part of the menstrual cycle. When a period is late, it is understandable to question the role of an ovarian cyst. Certain types of ovarian cysts can directly affect the timing of the menstrual cycle, often leading to a noticeable delay in the start of the next period.
Ovarian Cysts and Menstrual Cycle Timing
Ovarian cysts are categorized into two main groups: functional and pathological. Functional cysts are the most common and are directly related to the hormonal processes governing the monthly cycle. These temporary structures, including follicular cysts and corpus luteum cysts, usually resolve on their own.
Follicular cysts form when the ovarian follicle fails to rupture and release the egg during ovulation. Corpus luteum cysts develop after ovulation but can delay the period if they continue to produce hormones past their normal lifespan. Functional cysts are the most likely candidates to cause a delayed period.
Pathological cysts, such as dermoid cysts or endometriomas, are not linked to the hormonal process of the menstrual cycle. These types rarely affect period timing unless they grow substantially large or cause complications like ovarian torsion. If a cyst impacts cycle timing, it is almost always a functional cyst or Polycystic Ovary Syndrome (PCOS).
How Cysts Interfere with Ovulation
A period delay caused by a functional cyst stems from interference with the hormonal cascade regulating menstruation. The primary mechanism involves the failure of the follicle to complete its job, specifically for a follicular cyst. This cyst forms when the follicle does not rupture to release the egg, meaning ovulation does not occur.
When ovulation is delayed or prevented, the body does not enter the luteal phase. This phase prepares the uterine lining and ends with a drop in progesterone, which triggers the period. The follicular cyst continues to grow and produce estrogen, disrupting the hormonal signals that lead to the shedding of the uterine lining.
In the case of a corpus luteum cyst, the structure remaining after ovulation continues to produce progesterone for too long. This prolonged production artificially maintains the uterine lining, delaying the hormonal drop that signals menstruation. The period remains absent until the cyst shrinks and the progesterone level falls, which can delay the cycle by days or weeks.
Common Reasons for a Delayed Period
While an ovarian cyst can cause a delayed period, a late cycle is often the result of other common factors. Stress is a significant factor, as chronic emotional or physical stress causes the body to produce cortisol, which disrupts communication between the brain and the ovaries. This disruption can postpone ovulation and delay the start of the period.
Fluctuations in body weight, such as rapid weight loss or substantial weight gain, can lead to hormonal imbalances that interfere with the menstrual cycle. Increased intensity or duration of exercise can also cause a period to be late or absent. Changes in birth control methods, especially starting or stopping contraceptives, can temporarily alter the cycle’s predictability.
Underlying medical conditions, such as thyroid disorders or Polycystic Ovary Syndrome (PCOS), are frequent causes of irregular or delayed periods. PCOS is characterized by hormonal imbalance and the presence of multiple small follicles, which prevents regular ovulation.
When to Seek Medical Attention
While most functional ovarian cysts are harmless and resolve without intervention, a delayed period or accompanying symptoms may warrant a medical evaluation. Contact a healthcare provider if your period is late by more than a week, especially if you have recurrent cycle delays. A doctor can perform an ultrasound to determine if a cyst is present and assess its size and type.
Immediate medical attention is necessary if a delayed period is accompanied by severe, sudden pelvic or abdominal pain. This acute pain, often paired with vomiting or fever, could signal a serious complication like a cyst rupture or ovarian torsion. Red flag symptoms requiring emergency care include dizziness, light-headedness, or signs of shock.