#### Summary points
Unscheduled vaginal bleeding—bleeding that occurs outside the normal menstrual period or the regular withdrawal bleed associated with the combined oral contraceptive pill—is a common reason for women of reproductive age to attend primary care. It is also referred to as intermenstrual bleeding. As well as intermenstrual bleeding, unscheduled bleeding also includes postcoital bleeding; it can be difficult to distinguish between the two because they often occur together. Because postcoital bleeding may have different implications, the causes of both need to be considered in a woman with unscheduled bleeding. Irregular bleeding associated with hormonal contraception is generally called breakthrough bleeding.
In a study of women presenting to primary care with menstrual problems, 36% of women reported intermenstrual bleeding or postcoital bleeding in addition to heavy menstrual loss.1 Unscheduled bleeding causes anxiety and concern because it can be a presenting symptom for gynaecological cancer, particularly cervical and endometrial cancer. This symptom can also be associated with other menstrual disorders, such as heavy menstrual bleeding, particularly when caused by benign lesions such as fibroids or endometrial polyps, but also heavy menstrual bleeding of no known cause (formally called dysfunctional bleeding).
However, it …