Pus that appears on the body is a sign of an infection, which is generally caused by bacteria. Not only on the surface of the skin, pus can also form in internal organs, such as the urinary tract, mouth, eyes, brain, and lungs. Check out the various causes of the appearance of pus in the body and how to deal with the following! Pus can be recognized as thick, yellowish-white thick liquid, sometimes green or brown in color and smell bad. Pus fluid contains white blood cells, bacteria, and dead body tissue. Causes of Pus formation Pus appears as the body's natural reaction when fighting infection, or the body's inflammatory response to bacterial infection, and sometimes to fungus. Infection will cause pus when bacteria enter the body through injured skin, inhaled when coughing or sneezing, and due to unhygienic habits. When an infection occurs in certain parts of the body, white blood cells called neutrophils will gather in that part of the body and fight against the bacte