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Pneumonia is an infection that affects the lungs and can lead to inflammation in the air sacs. It may be caused by various organisms, including bacteria, viruses, and fungi. Symptoms can vary in intensity and may affect breathing and overall health. It's important to understand more about how pneumonia can impact daily activities.

Lungs & Respiratory
  • What exactly is pneumonia?
    MedlinePlusMay 2026

    Pneumonia is an infection in one or both lungs that causes the air sacs to fill with fluid or pus. It can be caused by bacteria, viruses, or fungi, and can range from mild to severe depending on what's causing it and your overall health.

  • How does pneumonia affect my lungs?
    MedlinePlusMay 2026

    When you have pneumonia, the air sacs in your lungs fill with fluid or pus instead of air. This makes it harder for your lungs to get oxygen into your blood, which is why you may feel short of breath or tired.

  • Can I get pneumonia more than once?
    MedlinePlusMay 2026

    Yes, you can get pneumonia more than once. Having pneumonia once doesn't give you permanent protection, so it's possible to catch it again in the future.

  • Why am I at risk for getting pneumonia?
    MedlinePlusMay 2026

    Your risk for pneumonia depends on factors like your age, overall health, whether you smoke, and if you have other health conditions. People with weak immune systems, chronic diseases, or who are very young or elderly are at higher risk.

  • Does having a weak immune system make me more likely to get pneumonia?
    MedlinePlusMay 2026

    Yes, a weak immune system makes you more likely to get pneumonia and more likely to have a serious case. Your immune system normally helps fight off the germs that cause pneumonia.