To survive, your body needs oxygen from the air you breathe. The lungs are designed to absorb the oxygen, transfer it into the bloodstream and to remove waste gases, such as carbon dioxide.

When you breathe air in through your nose or mouth, it travels down the back of your throat (pharynx), passes through your voice box (larynx), and into your windpipe (trachea). 

Your trachea is divided into two air passages (bronchial tubes). One leads to the left lung, the other to the right.

The right lung has three sections, called lobes, and is a little larger than the left lung, which has two lobes.

The bronchial tubes divide into smaller air passages (bronchi), and then into bronchioles.

The bronchioles end in tiny air sacs called alveoli, where the oxygen and carbon dioxide are exchanged in your blood.

After absorbing oxygen, the blood leaves the lungs and is carried to the heart. Then, it is pumped through your body to provide oxygen to the cells of your tissues and organs. When the oxygen is used by the cells, carbon dioxide is produced and transferred into the blood. Your blood carries the carbon dioxide back to your lungs and it is removed when you breathe out.

Lung (or respiratory) conditions affect how the lungs do their job. If the amount of air getting into the lungs is reduced or if the amount of oxygen being transferred to the blood is reduced, then you will have difficulty breathing and tire easily. Other difficulties can occur because the tissues and organs aren’t getting the oxygen they need.

For more information download our Understanding & Living with COPD booklet.