What Is Pus?

Pus—also known as liquor puris—is a thick white, yellow, green-colored fluid made up of dead white blood cells, tissue debris, and bacteria. When you develop an infection, your body's immune system produces pus as it fights the infection and tries to rid your body of bacteria or fungi.

Anyone can develop pus on their body when they become sick with an infection. But you may be more likely to notice pus-filled bumps or wounds if you have a weakened immune system, which raises your risk of infection. Fortunately, antibiotic medication can treat pus quickly. But seeking medical care is important as untreated infections can cause complications.

Where Does Pus Develop?

Pus can develop anywhere on your body when you have an infection. Sometimes, you can easily see pus growing from inside a wound on top of your skin. Other times, it isn't as easy to see pus forming—like when it happens deep in your tissues or organs.

You might develop pus in the following areas:

• Furuncles: Also known as boils, a furuncle is a small collection of pus in a hair follicle and the tissue around it.
• Surgical sites: After you have surgery, an infection can sometimes develop and cause pus to occur in the area of your body where the surgery took place.
• Venous ulcers: This type of ulcer is an open sore on your leg, which develops when your leg veins can't circulate blood well. Pus starts to grow when the ulcer becomes infected. 
• Conjunctivitis: Also known as pink eye, conjunctivitis is an eye infection. When you have bacterial conjunctivitis, you may notice pus from the eye that causes your eyelids to stick together.
• Abscess: An abscess is a collection of pus that can form in any part of the body. The skin and the teeth are common sites for abscesses to develop. Internal organs can also develop abscesses.
  
• Cystic acne: This type of acne causes pus-filled acne cysts to develop under your skin—most commonly on the face.

Symptoms

The symptoms of pus will depend on where the infection is present in your body. You may have other symptoms of an infection, such as fatigue, fever, swelling, tenderness, and a general feeling of being sick.

Symptoms of pus might also include:

• Pain
• Skin that is warm to the touch
• Redness
• Itching
• Oozing
  

Causes

When your body develops an infection, your immune system sends in its natural defense to fight off this infection. This action is known as inflammation. During the inflammatory process, your body sends white blood cells to attack the harmful pathogen (e.g., bacteria, fungi, or virus) that's causing the infection. As your body fights off the harmful cells, you can develop of build-up of pus in your tissues.

Risk Factors

People who have an autoimmune disorder, are immunocompromised, take immunosuppressant medications, pregnant people, young children, and older adults are all among the groups of people who are more likely to develop infections. As a result, they are also more likely to experience pus on their bodies.

Diagnosis

If you develop pus-filled bumps on your body, it's a good idea to check in with your healthcare provider. During your appointment, your provider will ask about your symptoms, perform a physical exam by looking at your skin, and order tests to see if pus is also forming deep in your skin or inside your organs. In some cases, your provider may also take a sample of your pus to determine which bacterial infection is causing your symptoms.

Your healthcare provider may order the following tests:

• Blood tests: A white blood cell count (WBC), sedimentation rate (ESR), and C-reactive protein (CRP) are helpful blood tests to detect active infections.
• Imaging: Imaging tests, such as an ultrasound, computed tomography scan (CT), magnetic resonance imaging (MRI), and X-ray can help detect the location of pus inside the body. These tests may also show if any bacteria has spread.
• Wound culture: By collecting a sample of your bus, a wound culture test can determine which bacteria is present in your body. To take a sample of your pus, your provider will either swab your skin where the pus is occurring or collect fluid through a needle or biopsy.

Treatment

Knowing what is causing your pus is important as this guides your provider in how to treat your infection. Your treatment plan will depend on the part of the body that is experiencing pus and the severity of your infection. The goal of treatment is to clear the infection and prevent complications from occurring.

Your treatment options may include:

• Antibiotics: When your healthcare provider knows what bacteria is causing the infection, they can prescribe the right antibiotic medication to help clear the infection. You can either apply an antibiotic ointment directly on your skin or take an oral pill to reduce symptoms.
• Medical procedures: If your infection is causing a large collection of pus and has created an abscess or wound, your provider may recommend injecting an anesthetic and draining the area. They do this by making a small cut into the abscess and gently applying pressure to release the pus from the wound. Once the area has been fully drained, your provider will place a sterile bandage or gauze on the skin to help it heal.
  

How to Prevent Pus

To prevent pus from occurring, you have to focus on the root cause of pus, which is preventing an infection. Keep in mind: it can be hard to completely prevent some infections, even if you're not immunocompromised. But, there are measures you can take to lower your risk of an infection or prevent your infection from getting worse. These strategies include:

• Washing your hands with soap and water regularly
• Cleaning your skin properly if you develop a cut on your skin
• Applying an over-the-counter antibiotic ointment to the site of a cut or wound to reduce the likelihood of an infection
• Keeping wounds covered with bandages or gauze so they can heal
• Seeking medical attention as soon as you can if you develop a more serious wound that you can't treat at home
  

Complications

Most of the time, infections that cause pus are treatable without causing additional harm. But, if you leave an infection untreated, you can develop some complications. For instance, some bacterial infections may cause your skin to develop a protective layer called biofilm. This biofilm can make an infection hard to detect and treat, causing wounds to become chronic.

Other possible complications of untreated pus include:

• Repeat infections
• Infections that spread into the bloodstream or bones
• Gangrene, a potentially fatal condition that occurs when blood flow to the infected tissue gets cut off and dies

A Quick Review

Pus develops on your body as your immune system tries to fight off an infection. If you develop pus on your skin, you might notice white, yellow, or green-colored fluid that causes pain, itching, or oozing. In most cases, antibiotic treatment can get rid of your infection and the associated pus. But if your symptoms aren't clearing up, talk to your healthcare provider and receive medical treatment as soon as you can to avoid complications from occurring.