What are healthy and unhealthy lungs, and when is lung transplant necessary?

Your lungs' main job is to make oxygen available to your body and to remove other gases, such as carbon dioxide. This process is done 12 to 20 times per minute.

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

Your trachea is divided into two air passages (bronchial tubes). One bronchial tube leads to the left lung, the other to the right lung. 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, which pump oxygen from the inhaled air to the 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.

After the oxygen is delivered to the cells, other gases are still in your blood. Your blood carries these gases back to your lungs and removes them when you exhale.

The respiratory system has built-in methods to prevent harmful substances from entering the lungs:

  • The hair (cilia) in your nose helps filter out large particles
  • Mucous produced by cells in the trachea and bronchial tubes keeps air passages moist and aids in intercepting dust, bacteria and other substances.
  • Cilia in the air passages move in a sweeping motion to keep the air passages clean. If substances such as cigarette smoke are inhaled, the cilia stop functioning properly.


What is the difference between healthy lungs and unhealthy lungs?

Each person is born with two lungs but can survive with only one as long as that lung is healthy. Healthy lungs are made of a spongy, pinkish-grayish tissue. Lungs that have become polluted with harmful carcinogens (substances that can cause cancer) or carbon particles have blackened spots on the surface. Healthy lungs may also have blackish spots, however, they are sporadic and not as abundant as in unhealthy lungs.

Healthy lungs are elastic so they can expand when you inhale; in contrast, a disease like emphysema causes the lungs to lose their elasticity. When a lung can no longer expand properly or transfer oxygen to the blood, that person has difficulty breathing and tires easily. In some cases, he or she can not walk more than a few steps at a time. Other difficulties may occur because the tissues and organs aren't getting the oxygen they need.

In some lung disorders, removing part or all of the lung can effectively treat the problem. But if a disease affects both lungs, or when medical treatment has not improved the lung condition, the best treatment choice may be a lung transplant.

A lung transplant may be recommended for patients with diseases such as cystic fibrosis, pulmonary fibrosis, chronic obstructive pulmonary disease (a group of diseases that includes emphysema) or pulmonary hypertension.

Before a lung transplant, you can expect to have a pre-transplant evaluation, which includes a complete physical, consultations with members of the Lung Transplant Team and a series of tests. A pre-transplant evaluation provides complete information about your overall health and helps determine if you are eligible for a lung transplant.

After your healthcare provider has determined that you are a good candidate for a lung transplant, the search for a donor will begin. Locating a suitable donor takes time and the waiting period may be stressful.

After a donor is found, things move quickly. You'll come to the hospital immediately, undergo surgery, and remain in the hospital for 2 to 3 weeks or longer, depending on your recovery.

During your recovery, you will learn about your new medications, how to recognize signs of complications, and when you can return to your normal activities. After you go home, you can expect to recover gradually, usually over 3 to 6 months.

Follow-up care after your transplant includes appointments with your doctor and tests to assess how your new lung is functioning and how the medications are working.

Last reviewed by a Cleveland Clinic medical professional on 05/02/2018.


  • National Heart, Lung and Blood Institute. How the lungs work. (http://www.nhlbi.nih.gov/health/dci/Diseases/hlw/hlw_what.html) Accessed 5/2/2019.
  • National Heart, Lung and Blood Institute. Lung Transplant. (http://www.nhlbi.nih.gov/health/dci/Diseases/lungtxp/lungtxp_whatis.html) Accessed 5/2/2019.

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