K64.5: Perianal venous thrombosis

Perianal venous thrombosis, commonly known as external hemorrhoids, is a medical condition characterized by the formation of a clot (thrombosis) in the small veins located around the outer edge of the anus (perianal region). This often presents as a painful swelling or lump near the anus, and it may be uncomfortable or painful, especially during bowel movements. The condition typically occurs as a result of increased pressure on the veins in the lower rectum, possibly caused by factors like straining during bowel movements, prolonged sitting, pregnancy, or obesity. In many cases, the clot will dissolve on its own over time, but sometimes it can persist and cause prolonged discomfort. Other symptoms that may accompany this condition include redness, inflammation, and a noticeable hard lump near the anus. In some cases, it can also cause rectal bleeding, although this is less common.