Irregular menstruation

What it means

Abnormally high variation in the amount of time between periods.

Most women have between 11 and 13 menstrual periods each year. Bleeding usually lasts around 5 days (range: 2 to 7 days). When menstruation first starts, it can take up to 2 years to establish a regular cycle. After puberty, most women's menstruation is regular. The length of time between each period is similar. The normal menstrual cycle length is 28 (+/- 7) days days with the menstruation lasting between 2 and 7 days. It can take up to 2 years from menarche to develop a mature hypothalamic-pituitary-gonadal (HPG) axis. Within 1 year, 75 percent of girls have a cycle between 21 and 45 days. By the fifth gynecological year, 90 percent of girls will have regular cycles.

Rare diseases that can present with this17

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Irregular menses · Irregular periods · Menstrual irregularities