An endometrial biopsy is a medical procedure used to collect a small sample of tissue from the lining of the uterus, known as the endometrium. This test is often performed to investigate abnormal uterine bleeding, check for conditions like endometrial hyperplasia, or to rule out endometrial cancer. The procedure can be done in a doctor's office and typically takes only a few minutes. During the biopsy, a healthcare provider uses a thin tube to remove a small piece of tissue. Patients may experience mild discomfort or cramping, but serious complications are rare. The collected tissue is then examined under a microscope for any abnormalities.