Pneumocystis pneumonia (PCP) is a form of pneumonia. It affects
people who have a weakened immune system. PCP is the most common
serious infection among people with AIDS . PCP is caused by a
fungus. Most believe that the fungus is spread in the air but it
is not clear if the fungus lives in soil or elsewhere. In
healthy people, the fungus can exist in the lungs without
causing pneumonia. However, in people who have a weakened immune
system, the fungus can spread and cause a lung infection. A
weakened immune system can put you at risk for PCP. The immune
system may be weakened in people who: - Have AIDS - Have cancer
- Are getting treatment for cancer - Are using medications that
may weaken the immune system such as steroids Symptoms of PCP
usually develop over the course of a few weeks or months. The
main symptoms of PCP are: - Shortness of breath - Dry cough -
Tightness or pain in the chest See your doctor immediately if
you have any these symptoms. Your doctor will ask about your
symptoms and medical histor