What an infected foot looks like, how to tell it apart from ordinary irritation, and the signs that mean you shouldn't wait.
Feet take a beating — cuts, blisters, ingrown nails, and cracked skin are everyday occurrences. Most heal fine. But any break in the skin is a doorway for bacteria, and on the foot, infections can take hold quickly and be easy to miss. Knowing what an infected foot looks like helps you act before a small problem becomes a serious one.
The simplest rule of thumb: healing gets better each day; infection gets worse. If a wound is spreading, increasingly painful, warm, or leaking pus, treat it as infected.
Skin around the wound turns red, and the redness often spreads outward over time.
The area puffs up; skin may look tight or shiny.
The infected area feels noticeably hotter than the surrounding skin.
Yellow, green, or cloudy fluid leaking from a cut, blister, or sore.
Throbbing or increasing pain rather than the steady improvement of healing.
A foul odor from the wound is a strong sign of bacterial infection.
A cut, blister, or sore that stays open or gets worse over a week or more.
Red lines spreading up the foot or leg — a sign the infection is spreading. Seek care now.
Have diabetes or poor circulation? Don't wait and watch. Nerve damage can hide pain and reduced blood flow slows healing, so even a small infected spot needs prompt attention. See our diabetic wound care guide.
The classic signs of an infected foot are redness, swelling, warmth, and pain that get worse over time rather than better, often with pus or drainage. Other clues include a wound that won't heal, a bad smell, red skin spreading outward, and sometimes fever. Normal healing should steadily improve day by day — if it's worsening, spreading, or producing pus, treat it as an infection and get it checked.
An infected foot typically looks red and swollen, with the redness often spreading beyond the original wound. The skin may look shiny, feel hot to the touch, and there may be yellow or green pus, crusting, or fluid leaking from a cut or sore. Serious infection can show red streaks running up the foot or leg, blisters, or dark/black tissue. A photo can't replace an exam — if it looks infected, have it evaluated.
Very mild surface irritation can settle on its own, but a true bacterial foot infection usually does not — it tends to spread without treatment. Relying on it to clear by itself risks the infection moving into deeper tissue or bone. If you have any spreading redness, pus, increasing pain, or you have diabetes or poor circulation, see a podiatrist rather than waiting.
Irritation (from rubbing, a blister, or mild inflammation) usually stays localized, improves with rest, and doesn't produce pus or fever. An infection typically worsens over hours to days, spreads outward, feels increasingly warm and painful, and may leak pus or smell bad. The direction matters most: getting better = likely irritation; getting worse = likely infection.
Gently clean and cover the area, keep weight off it, elevate the foot, and avoid trying to drain it yourself. Then have it evaluated promptly — within a day for most people, and the same day if you have diabetes or poor circulation. Go to the ER for fever, red streaks up the leg, or black tissue, which can mean the infection is spreading dangerously.
It's always better to have it checked early. Our board-certified podiatrists diagnose and treat foot and toe infections at three South Chicago suburbs locations — Homewood, South Chicago Heights, and Mokena.