What is pus?
The word “pus” conjures all kinds of unpleasant images. It’s linked with injuries and infection and no one likes to think about that.
Pus is a thick fluid that builds up when an injury becomes infected. It can be white, yellow, green, or brown. It may have a foul odor but that is not always the case. It may have no scent at all.
Once an infection has started, your immune system begins trying to fight it off. It sends white blood cells to the area to destroy the bacteria. The white blood cells wear out and die after a while, as does some of the injured tissue. The residue collects in the injured area and becomes what we call pus.
Learn more about pus, why it appears, and how to treat an infected wound.
Signs of pus and wound infection
Pus isn’t the only symptom of an infection. The area will usually look red and swollen. It may be warm to the touch and the infected spot could be painful. If the situation gets worse, you might notice symptoms like fever, aches, or chills as your body fights the infection.
Causes of pus and wound infection
Pus often shows up in an abscess, a space that develops when there is a breakdown in your body’s tissue. When the outer layers of skin break for any reason, bacteria can enter the wounds and cause an infection. Abscesses can occur on the body, including the skin, mucus membranes, or your internal organ.
Skin abscesses are very common. Anything from a small cut to an ingrown hair can be a point of entry for bacteria. Sometimes these small wounds get infected and come to a head, similar to a pimple. There will be a pocket of pus visible on top of a red, painful bump.
Infections can also happen below the skin. When that happens, you may notice a swollen, red area that is painful to the touch. You can’t see it, but pus is collecting in the abscess. If you don’t get treatment, the infection can worsen or spread.
Surgical wounds are also at risk for infections. You may notice new or worsening pain around the incision if it gets infected. Swelling and redness are signs of infection, along with any pus that soaks through bandages or comes out in a drainage tube.
When to see the doctor for pus and wound infection
If the infection is small — less than half an inch across — you can probably treat it at home with warm compresses.
You should see a doctor if you have a sore that is larger than half an inch. Also, call the doctor if a small wound gets bigger or more painful or if you have a fever. You should also see a doctor if the area develops red streaks, which might mean the infection is spreading.
Diagnosis of pus and wound infection
When you see your doctor, they will want to know how the injury happened and how long you have had the infection. They will examine the wound and the surrounding area to get an idea of how large the infection might be.
Treatments for pus and wound infection
Pus-filled abscesses often need to be drained in order to heal completely. Your doctor will decide how to do that based on where the abscess is on your body. It could be something the doctor can do in the office or you might need a more extensive procedure.
Dental abscesses can be treated in the office. Your dentist will numb the area and clean out the infection. You will probably need a root canal to solve the problem.
After the pus is cleaned out of the wound, your doctor may give you antibiotics to prevent it from coming back. You should take any medication as directed. You should also follow all the instructions your doctor gives you about caring for the wound when you get home.
Health Solutions From Our Sponsors
National Health Service UK: "Abscess."
National Health Service UK: "Dental Abscess."
The Ohio State University Wexner Medical Center: "Six signs your wound isn't healing right."
U.S. National Library of Medicine: "Surgical wound infection - treatment."