Pneumonia can have many manifestations, and each person's symptoms can be different. It is highly heterogeneous, varying from mild to severe and can last for short or long durations. The main factors depend on the type of pathogen involved and the state of the body. The most common symptoms of pneumonia are coughing and producing sputum. The cough can be mild or severe and may be accompanied by sputum. The amount of sputum can vary and may be yellow, green, red, or rust-colored. Other possible symptoms include chest pain, difficulty breathing, respiratory distress, and most cases of pneumonia also involve fever. The duration and severity of the fever are somewhat related to the course of the illness. However, a small portion of patients may have atypical symptoms, especially older adults, who may not show direct respiratory symptoms but instead exhibit consciousness disturbances such as coma, confusion, fatigue, and more.