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Learning About How the Lungs Work

Lungs in chest, with detail of air sacs (alveoli) and exchange of carbon dioxide and oxygen in blood.

What do your lungs do?

Your lungs are part of the respiratory system. The main job of the lungs and the respiratory system is to give your body oxygen and move waste products, such as carbon dioxide, out of your body. This happens when you breathe. This process is called respiration.

When you breathe in, air enters your lungs. Your lungs move oxygen from the air into your blood. The blood carries the oxygen to every cell in your body. It also picks up carbon dioxide from the cells and carries it back to the lungs. When you breathe out, you push the carbon dioxide out of your lungs and your body.

Breathing is automatic. Your body adjusts when you need more or less oxygen. There are sensors in your brain that know when you need more oxygen or less carbon dioxide in your blood and cause you to breathe harder.

Your lungs do more than move oxygen in and carbon dioxide out of the body. They also act as filters. Mucus in your lungs catches and holds dust, germs, and other things that have entered the lungs. When you cough, sneeze, or clear your throat, you move this material out of your body.

What problems can happen in your lungs?

Your lungs are different from many other organs because they are in contact with the outside world. You may breathe in dust, pollen, viruses, bacteria, cigarette smoke, air pollution, and exhaust fumes. Anything you breathe in can harm how well your lungs work and can make breathing harder and a lung problem more likely.

For example:

  • A virus or bacteria can cause infections such as a cold or pneumonia.
  • Pollen or dust can cause allergies.
  • Air pollution, such as cigarette smoke or wood smoke, can make it harder to breathe, especially if you have a lung disease such as COPD (chronic obstructive pulmonary disease) or asthma.
  • Cigarette smoke can lead to lung cancer or COPD.

If you have a lung disease, what you breathe in can suddenly make symptoms worse. For example, breathing in cigarette smoke can cause an asthma attack or a COPD flare-up.

How can you prevent lung problems?

  • Do not smoke or allow others to smoke around you. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
  • Try to avoid pollution that can harm your lungs. Dust in the air, wood smoke, and chemicals at home and in the workplace can all harm your lungs.
  • Try not to exercise outside when the air is bad.
  • Follow directions and use appropriate safety equipment if you work with chemicals. Store them as instructed.
  • If you have a lung problem, be extra careful.
    • Something you breathe in could make your symptoms worse. Talk to your doctor about what things might trigger a breathing problem, and try to avoid them.
    • Avoid infections such as COVID-19, colds, and influenza (flu). Wash your hands often. A cold or other lung infection could become serious. Get a flu vaccine every year. Stay up to date on your COVID-19 vaccines. Ask your doctor if you need the pneumococcal and whooping cough (pertussis) shots.

Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.