A pneumonia diagnosis is usually based on signs and symptoms in combination with chest imaging (e.g., X-ray or computed tomography) that shows signs of a lung infection. Since pneumonia presents similarly to other medical conditions, it is important to see a clinician for a diagnosis. A clinician will acquire a medical history and conduct a physical assessment to guide the choice of any necessary treatments, imaging, and/or blood tests. These tests will help rule out other possible causes of symptoms, like the flu, asthma, or pulmonary embolism.