A hysteroscopy is a procedure that uses a hysteroscope (a thin, lighted viewing instrument) to see inside the uterus and observe whether there is any abnormal tissue, particularly in the endometrial cavity, which is the layer of mucus membranes that line the uterus. This helps your provider diagnose issues with the uterus such as fibroids or polyps (diagnostic hysteroscopy).
They can also perform minimally invasive procedures using the hysteroscope to see what they're doing.