Some hemorrhoids will cause anal pain, some hemorrhoids will not cause anal pain, as follows: 1, no pain: internal hemorrhoids occur in the anus on the dentate line, the dentate line by the vegetative nerve innervation, the vegetative nerve belongs to the painless sensory nerves, so the internal hemorrhoids painless, and will not cause anal pain. If the external hemorrhoids for connective tissue external hemorrhoids, manifested as the anal margin of the skin tissue, will not cause anal pain. 2, there is pain: when the internal hemorrhoids out of the anus, can not be returned to the anus, and sometimes appear incarcerated, out of the internal mole due to the sphincter clamping, the blood circulation around the obstacle, the internal hemorrhoids will be swollen and painful, causing anal pain. When thrombus or inflammation occurs in external hemorrhoids, swelling and pain will also occur. After treatment, the inflammation subsides and the thrombus is absorbed, the swelling and pain will be relieved or disappear.