A hemorrhoid is a swollen vein in the anus or rectum, the last part of the large intestine. Thrombosed hemorrhoids happen when a blood clot forms inside a hemorrhoid. The blood clot blocks blood flow, causing painful symptoms.
Most thrombosed hemorrhoids are external, but they can also be internal. External hemorrhoids form in the tissue outside the anus, while internal hemorrhoids are inside.

Thrombophlebitis is inflammation of the walls of surface veins, which is accompanied by the formation of blood clots. Most often, the pelvic organs and legs are involved in the process. The development of the disease can lead to the appearance of threatening consequences. You can not postpone thrombophlebitis treatment.