Pneumonia is a respiratory infection that inflames the air sacs in one or both lungs, causing symptoms like coughing, fever, and difficulty breathing. Pneumonia can be caused by viruses, bacteria, or fungi, and the contagious period varies depending on the specific cause. Understanding how long someone with pneumonia is contagious can help protect others from getting sick, especially those at higher risk such as infants, elderly adults, and people with weakened immune systems. Keep reading ...