Medically Reviewed by Paul Boyce, MD on May 20, 2020

Inhale, Exhale


Without healthy lungs, it can be harder to get all the oxygen that every cell in your body needs.  When you breathe in, your lungs fill with oxygen-rich air that moves into and circulates through your bloodstream. Most of the time, your lungs do this crucial work without you noticing it. But many health conditions can make it less easy to breathe comfortably and effectively.

Chest Cold (Acute Bronchitis)


Hundreds of viruses can cause the common cold, and most of the time when you catch one, your nose and throat bear the brunt of your symptoms. But sometimes a run-of-the mill cold turns into a "chest cold," which doctors refer to as acute bronchitis. This condition makes your bronchial tubes (airways in your lungs) swell and make more mucus, which can lead to a bad cough and chest discomfort. Acute bronchitis usually goes away on its own within a few weeks.



Asthma also causes swelling of the airways and mucus in the lungs, but it's a chronic -- usually lifelong -- condition rather than a temporary one caused by an infection. If you have asthma, your lung capacity may be lower because swelling and mucus limit the movement of air in your lungs. During an asthma attack, the airways narrow, which may make you wheeze and can become dangerous. 



Allergies to triggers like pollen, dust, and pets don't usually affect the lungs. But allergies and asthma often go hand-in-hand. If you have both conditions, being exposed to an allergen like pollen can trigger an asthma attack.



The most serious type of allergic reaction, called anaphylaxis, certainly affects the lungs. Anaphylaxis is most likely to happen when someone who has a severe allergy to a food, insect sting, medication, or latex is exposed to that trigger. Your body goes into shock, airways constrict, and your throat may become so swollen that enough air can't pass through. Anaphylaxis is a life-threatening medical emergency, so call 911 right away and use your epinephrine injector.

COPD (Chronic Obstructive Pulmonary Disease)


COPD is an umbrella term that includes chronic bronchitis and emphysema. It usually develops in people who’ve smoked for a long time. Most people with COPD have some symptoms of both chronic bronchitis and emphysema. Bronchitis refers to inflammation in the bronchial tubes in the lungs. Emphysema happens when the tiny air sacs in the lungs, called alveoli, are destroyed. Air can get trapped in the damaged tissue. As a result, not enough oxygen makes it from the lungs into the bloodstream.

Influenza (Flu)


The flu can make you miserable for a number of reasons, including fever, body aches, and a dry cough. The virus that causes the flu can infect the epithelial cells in your lungs and start reproducing itself within your lung tissue. That leads to more inflammation as immune cells in the area try to fight back to get rid of the virus. The flu may also harm your lungs because it makes you more likely to get another infection, such as pneumonia.



Whether it follows the flu or strikes on its own, pneumonia affects the lobes or airways (bronchi) of the lungs. This condition, which may be caused by bacteria or a virus, causes the air sacs to fill with liquid and pus. People with pneumonia often cough up mucus, breathe rapidly, feel short of breath, and have sharp chest pain.



COVID-19 can harm the lungs in a few ways. As with the flu, some people who get the new coronavirus that causes COVID-19 will develop pneumonia as a complication. In that case, the air sacs fill with fluid. For some people, pneumonia related to COVID-19 becomes so severe that it leads to acute respiratory distress syndrome (ARDS). This is a type of lung failure caused by damage to lung tissue. People with ARDS are very short of breath and may need to be put on a ventilator, a machine that "breathes" for you.

Tuberculosis (TB)


This infectious disease happens when a specific type of bacteria reaches the alveoli (tiny air sacs) in the lungs. Some people who carry this bacteria don't know that they do, but others develop serious symptoms. Either way, the infection can damage your lungs.

Cystic Fibrosis


Cystic fibrosis is caused by an inherited, defective gene. In people who have it, the cells that make mucus, sweat, and digestive juices are thick and sticky instead of thin and slippery. This clogs passages in the body, including those in the lungs. People who have this disease often cough up mucus, wheeze, and get frequent lung infections.

Lung Cancer


Lung cancer develops when cells in the lungs grow and cluster together into a tumor. As tumors grow, they destroy healthy tissue around them. If a tumor in your lungs becomes large enough, it can block an airway and make it harder to breathe. Cancer can also start in other parts of the body and spread to the lungs, but that’s not lung cancer. For instance, breast cancer that spreads to the lungs is still breast cancer.

Interstitial Lung Disease (Pulmonary Fibrosis)


This includes about 100 chronic disorders that cause inflammation and scarring (fibrosis) in the lungs. The buildup of scar tissue ends up destroying the air sacs and capillaries in the lungs and makes it hard to get enough oxygen. Eventually the lungs stiffen, and it becomes more and more difficult to breathe

Heart Disease


Your lungs and heart work closely together, so when one is taxed, the other often suffers. Some heart problems can lead to pulmonary hypertension, a type of high blood pressure in the arteries in your lungs and the right side of your heart. Over time, blood vessels in the lungs narrow so it's harder for blood to flow through. In other cases, people with heart problems develop pulmonary edema, which is a buildup of fluid in the air sacs in the lungs that makes it hard to breathe.

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American College of Allergy, Asthma, and Immunology: "Anaphylaxis," "Signs of Asthma."
American Lung Association: "Chronic Bronchitis," "Emphysema," "Facts About the Common Cold," "How Lungs Work," "Learn About COPD," "Lung Cancer Basics."

CDC: "Chest Cold (Acute Bronchitis)."

Frontiers in Immunology: "Inflammation as a Modulator of Host Susceptibility to Pulmonary Influenza, Pneumococcal, and Co-Infections."

Johns Hopkins Medicine: "Anaphylaxis," "Interstitial Lung Disease: Pulmonary Fibrosis," "Pneumonia," "What Coronavirus Does to the Lungs."

Mayo Clinic: "Bronchitis," "Cystic Fibrosis," "Influenza (Flu)," "Pulmonary Edema," "Pulmonary Hypertension."

National Jewish Health: "Tuberculosis (TB)."

National Jewish Health: "Tuberculosis (TB)."