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 procedure helps doctors diagnose various conditions, such as uterine cancer, endometrial hyperplasia, or other abnormalities. It is typically performed in a doctor's office and may involve the use of a thin tube called a catheter. During the biopsy, the doctor inserts the catheter through the cervix into the uterus to obtain the tissue sample. Patients may experience mild discomfort or cramping, but the procedure usually takes only a few minutes. The collected tissue is then sent to a laboratory for analysis.