Tuberculosis (TB) Tuberculosis is a contagious infection caused by bacteria that usually affects the lungs. Common symptoms include a persistent cough, fever, weight loss, night sweats, and coughing up sputum. It is treated with a combination of antibiotics taken for several months. Pneumonia Pneumonia is an infection that causes inflammation of the air sacs in the lungs, which may fill with fluid or pus. Symptoms include cough, fever, chest pain, and shortness of breath. Treatment depends on the cause and may include antibiotics, antiviral medicines, fluids, and rest.