External hemorrhoids (a single lesion is shown here) are found below the dentate line (the division between squamous epithelium distally and transitional columnar epithelium proximally) and so are covered by skin. Patients experience significant pain when external hemorrhoids are dilated and thrombosed—conditions that stretch the overlying skin.
![External hemorrhoids](http://www.consultantlive.com/image/image_gallery?img_id=2111447&t=1351702454633alt="")
Photo courtesy of Allen P. Kong, MD and Michael J. Stamos, MD.
