血栓外痔是肛肠科常见的外痔 ,与内痔、混合痔和肛乳头肥大有关。便秘、腹泻、排粪用力、剧烈活动和咳嗽均使肛门缘的静脉突然破裂 ,血渗到皮下组织内形成肿块。肿块常呈圆形或椭圆形 ,在肛门缘皮下呈红紫色 ,较硬 ,触痛明显 ,大小不等 ,疼痛轻重不同。根据疼痛的轻重可把血栓? Thromboembolism is an external anorectal hemorrhoids common external hemorrhoids, and internal hemorrhoids, mixed hemorrhoids and anal nipple hypertrophy. Constipation, diarrhea, defecation force, violent activities and cough are caused by sudden rupture of the anus edge of the vein, the blood seepage into the subcutaneous tissue to form a mass. Often round or oval mass, in the anal margin of skin was purple, harder, obvious tenderness, the size range, different pain severity. According to the severity of pain thrombosis?