Laboratory Tests Used in Pneumonia Diagnosis
Laboratory testing is essential for identifying the cause of pneumonia and guiding targeted therapy. These tests help distinguish between bacterial, viral, and fungal infections.
Blood tests are commonly performed to evaluate infection markers. Elevated white blood cell counts and increased inflammatory markers suggest an active infection. Blood cultures are used to detect bacteria in the bloodstream, particularly in severe pneumonia cases.
Sputum testing is another key diagnostic method. Patients produce mucus from deep coughing, which is examined under a microscope and cultured to identify pathogens. This test helps determine antibiotic sensitivity.
Urinary antigen tests detect specific bacterial antigens, such as Streptococcus pneumoniae or Legionella pneumophila. These tests provide rapid results and are useful when sputum samples are difficult to obtain.
Viral testing has become increasingly important. Polymerase chain reaction (PCR) tests identify viral genetic material, allowing detection of influenza, respiratory syncytial virus, or other respiratory viruses.
Laboratory testing provides valuable information but may not always identify the pathogen. In such cases, treatment decisions are based on clinical judgment and disease severity.