Hemorrhoids are a swelling of veins under the skin of the anus or lower rectum. Hemorrhoids are commonly asymptomatic, and most patients are unaware they have them. However, hemorrhoids can flare, cause itching, bleeding, or leakage of feces and may or may not be associated with pain. The most common cause of hemorrhoids is straining, chronic constipation/diarrhea, pregnancy, age, and sitting for prolonged periods.