The presence of pneumonia is not usually detected by blood tests, but is often diagnosed by a CT or plain radiograph of the chest. Blood tests are often required when pneumonia is present. The main tests are C-reactive protein and routine blood tests to confirm the type of infection. If the pneumonia is caused by a bacterial infection, the blood test will show an increase in the number of white blood cells and an increase in C-reactive protein. This is the time to choose the appropriate antibiotic for anti-inflammatory treatment according to the type of infection, in order to be more effective. Generally penicillin can be administered intravenously if there is no allergy to penicillin or cephalosporins. If there is no allergy, intravenous Ceftriaxone can also be ordered, the effect is also better. If there are allergies to all of the above drugs, azithromycin can also be used for anti-inflammatory treatment, which is also more effective. Therefore, pneumonia cannot be detected by blood test, but needs to be confirmed by CT, MRI or plain film of the chest.