A perianal abscess is a pocket of pus next to the anus. It starts fast and hurts a lot, so most people notice it within a day or two.

Throbbing pain is the headline. It feels like a deep, steady drumbeat that gets worse when you sit, cough, or have a bowel movement.

Red, hot swelling shows up quickly. A firm, painful lump appears near the opening; the skin feels warm and looks shiny.

Fever and chills can tag along. You feel cold one minute, hot the next, and the thermometer can spike over 100.4 °F.

Pus drainage may start. A yellow or bloody streak appears on underwear, or you feel a sudden pop and relief when the abscess breaks.

Pain keeps you up at night. Even light pressure from sheets can feel like a knife.

Late signs include a large, soft mass or red streaks running up the skin—an alarm that the infection is spreading.