What Is Pneumonia?
Pneumonia is an infection that inflames the air sacs in one or both lungs. These sacs may fill with fluid or pus, causing symptoms such as cough with phlegm, fever, chills, and difficulty breathing. The severity of pneumonia can vary from mild to life-threatening, particularly in infants, elderly individuals, and those with weakened immune systems. Bacteria, viruses, and fungi can cause pneumonia, making early diagnosis and treatment essential for a full recovery.