Fever is a main symptom of PCP, along with a dry cough that doesn't produce any phlegm (sputum). Other chief symptoms include chest tightness and difficulty breathing. Fatigue and night sweats can also occur, often before breathing difficulties appear.
These are also symptoms of other types of infections, thus it is important to diagnose PCP carefully.
There is no blood test to determine if PCP is present in the body. To diagnose PCP, fluid (sputum) or tissue from the lungs is collected by a doctor and examined by a laboratory under a microscope. While X-rays can be used to determine how much fluid has collected in the lungs, they can't tell the difference between PCP and other lung infections like tuberculosis.