Lung infections occur when harmful germs, such as bacteria or viruses, invade the lungs, leading to inflammation and difficulty breathing. Common types of lung infections include pneumonia, bronchitis, and tuberculosis. Symptoms often include cough, fever, chest pain, and shortness of breath. These infections can affect anyone but are more serious for young children, the elderly, and individuals with weakened immune systems. Treatment typically involves antibiotics for bacterial infections and supportive care for viral infections. Preventive measures include vaccinations and good hygiene practices to reduce the risk of infection.