J17: Pneumonia in diseases classified elsewhere

Pneumonia in diseases classified elsewhere, coded as J17 in the ICD-10 WHO 2016 classification, refers to pneumonia, which is a lung infection, arising as a complication or associated symptom of other diseases. Pneumonia involves inflammation and fluid build-up in the lung tissue, making it difficult to breathe. Symptoms may include chest pain, cough, fever, and trouble breathing. Developing pneumonia can occur from various causes, including bacteria, viruses, or fungi, which are often present due to an existing illness. The existing illness might weaken the immune system, making the individual more susceptible to developing a lung infection. When it comes to progression, pneumonia can vary from mild to severe, and it greatly depends on the underlying disease, the specific organism causing pneumonia, the individual's age, and overall health. The respiratory system is particularly affected, though the infection can affect the entire body system if it becomes severe or is left untreated.