External hemorrhoids
External hemorrhoids are swollen areas of skin and blood vessels around the anus. They are highly innervated and sensitive and are also at risk for thrombosis.
They develop around the external opening of the anus. It is usually very painful as the skin around them is very sensitive.
Most of the time, they are just bothersome protrusions, which make hygiene and personal care very difficult. Many times, external hemorrhoids develop a clot inside of them. This can happen after a period of diarrhea or constipation. In such cases, it produces a firm and painful swelling or lump around the rim of the anus.