What are the symptoms of cellulitis?

Cellulitis is an infection in deeper layers of skin and the tissue beneath it. The affected area may feel hot, tight, sore, or painful, with redness that gradually expands rather than staying as a small, stable mark. The skin can look smooth and shiny, and swelling may make a limb feel heavy. Symptoms often affect one area, commonly a lower leg, foot, arm, or face. A break in the skin, bite, wound, ulcer, or another skin problem can provide an entry point, although the original opening may be hard to see. See [Skin Redness](/symptoms/skin-redness/) and [Painful Skin](/symptoms/skin-pain/) for related symptoms.

Contact a clinician promptly if you suspect cellulitis, because it can worsen without appropriate treatment. Keep the area clean, avoid squeezing or rubbing it, and mark the edge of redness with a pen so you can describe whether it is spreading. Rest and elevate a swollen limb when comfortable, but do not delay assessment. Tell the clinician about diabetes, immune problems, recent wounds, or insect bites. Do not use leftover antibiotics or share medicine; the choice and duration depend on the infection and your health. Read about [Insect Bites and Stings](/conditions/insect-bites-and-stings/) if a bite preceded the change.

Arrange same-day medical assessment for spreading redness, increasing warmth or pain, swelling, pus, or fever. Get urgent help for cellulitis around the eye, rapidly worsening facial swelling, severe pain out of proportion to the visible skin change, faintness, confusion, breathing difficulty, or marked weakness. These symptoms can signal a more serious infection; [Sepsis](/conditions/sepsis/) is a medical emergency. People with type 2 diabetes or reduced immunity should seek advice early, even when the skin change appears limited.

How extensive does the infection appear? Which treatment do I need, and when should improvement begin? How will I know if the redness is spreading? Should I have the wound, bite, or underlying skin problem checked?