External hemorrhoids can cause anal itching, external hemorrhoids are varicose vein clusters, it is usually in the case of increased abdominal pressure or constipation, resulting in hemorrhoidal vein stagnation and swelling and formation. External hemorrhoids are mainly divided into connective tissue external hemorrhoids, inflammatory external hemorrhoids, varicose external hemorrhoids, and thrombosed external hemorrhoids, the first, external hemorrhoids are sometimes accompanied by anal fissures, such as dry stools will stimulate anal skin fissures, so that fecal matter as well as mucus will lead to the trauma of itching. The second, hemorrhoids often out of the anus, it will sometimes stimulate fecal outflow leading to perianal skin itching, long-term mucus and fecal stimulation, easy to make the perianal skin discomfort. If the external hemorrhoid is relatively heavy, the stasis is more powerful, will form thrombosed external hemorrhoids, local visible oozing, such as blood, and combined with the infection will appear after the pus, will lead to perianal itching discomfort, because of local hemorrhoidal vein fibrous connective tissue will be swollen. Therefore, there are many reasons for the itching of external hemorrhoids, should be timely treatment of external hemorrhoids, so as to play a role in suppressing its symptoms.