COVID-19 is a disease that primarily affects the respiratory system. It is typically a short-term disease that lasts up to four weeks. Some people who develop COVID-19 have lingering symptoms over weeks or months. When COVID-19 symptoms begin or last for 12 weeks after the initial infection, the condition is known as long COVID. Long COVID can cause a variety of symptoms that impact breathing and lung function.

When COVID-19 Infects the Lungs

COVID-19 infection primarily impacts the lungs. After the coronavirus that causes COVID-19 has entered the body, it uses special receptors on the outside of cells known as ACE-2 receptors. These receptors are found on cells that line the airways in the respiratory system. After the virus binds to the receptors, it can travel inside the cells, where it hijacks them and uses them to make more copies of itself.

After infection takes hold, the virus quickly spreads through the respiratory system. The epithelial cells that line the airways are normally responsible for removing substances that enter the lungs from the air we breathe, such as pollen and other viruses. When these cells are infected, they lose the ability to clear these substances, and the lungs can become filled with fluid and other debris. Over time, this can make breathing difficult and cause other health issues.

Damage to the tiny air sacs in the lungs — known as alveoli — also occurs during COVID-19 infection. Alveoli are responsible for exchanging oxygen and carbon dioxide in the blood. When they become damaged, oxygen cannot reach the lungs and other tissues, and the lung tissue thickens and becomes stiff.

Underlying Health Conditions

People with chronic lung diseases who are infected with COVID-19 have a greater risk for developing more serious symptoms. This is because the lungs are already weakened from inflammation and damage.

Underlying conditions that can lead to more damage in a COVID-19 infection include:

• Asthma
• Chronic obstructive pulmonary disease
• Acute respiratory distress syndrome (ARDS)
• Cystic fibrosis
• High blood pressure in the lungs — known as pulmonary hypertension
• Scarring of the lungs — known as pulmonary fibrosis
• Lung cancer
• Being immunocompromised after an organ transplant

Long COVID Symptoms in the Lungs

In long COVID, symptoms last longer than 12 weeks. Lung damage caused by the coronavirus can lead to lasting symptoms, such as shortness of breath, dry cough, and chest pain. Other complications, such as pneumonia and blood clots in the lungs, can arise.

Common lung symptoms experienced by people with long COVID include:

• Persistent chest pain or pressure
• Difficulty breathing
• Shortness of breath
• Dry cough

Fatigue is also likely, because the lungs may provide less oxygen than they used to. If you were hospitalized for COVID-19, it is also common to experience exhaustion and severe weakness during recovery.

Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome is a serious lung condition that is often caused by another disease, such as a severe COVID-19 infection. In one study of 52 people hospitalized for COVID-19 and pneumonia in China, 67 percent had ARDS.

ARDS is caused by fluid buildup in the alveoli, which limits oxygen and carbon dioxide exchange. It also causes breakdown of a substance known as surfactant, which allows the lungs to expand for breathing.

When someone has ARDS, the lungs cannot properly fill with air, and the body does not receive enough oxygen. This can lead to scarring in the lungs, making it difficult for the tissues to fully recover and leaving a person vulnerable to long-term symptoms and complications.

Pneumonia

Pneumonia is a lung infection that causes the alveoli to fill with fluid. It can be caused by infections with viruses, such as COVID-19, or by bacteria or fungi. The main symptom of pneumonia is shortness of breath, because the alveoli cannot properly exchange oxygen in the lungs.

After infection with long COVID, there may be lasting lung problems that can affect your lung capacity — the amount of air your lungs can inhale. It may take months until breathing ability is fully restored.

Symptoms of pneumonia include:

• Fever
• Chills
• Chest pain from coughing or breathing
• Dry cough or cough with mucus
• Trouble breathing
• Low blood oxygen levels

One study found that roughly 73 percent of people hospitalized with COVID-19 had pneumonia, and that most still had some symptoms two months after their initial infection. Another study of 55 people who had been hospitalized for COVID-19 showed that 25 percent had signs of lung abnormalities 90 days after they left the hospital.

Pulmonary Embolism

COVID-19 can cause blood to form clots more easily. When these clots become too large to fit through blood vessels, they can become stuck and cause heart attack or stroke. If a clot gets stuck in the lungs, it can lead to a pulmonary embolism. This prevents blood and oxygen from reaching parts of the lungs, which could cause the lung tissue to die. The affected segment of lung tissue will no longer be able to absorb oxygen and release carbon dioxide, leading to more shortness of breath.

Symptoms of a pulmonary embolism include:

• Sharp chest pain that occurs when you breathe in deeply, bend over, or cough
• A cough that may produce bloody mucus
• Shortness of breath

Treatments for Lung Symptoms of Long COVID

Doctors and researchers are still looking into treatments for managing the long-term effects of COVID-19. Dealing with the effects of a long-term illness can be stressful, especially when there are no immediate answers for these symptoms.

The Centers for Disease Control and Prevention (CDC) recommends several ways to manage your stress and improve your overall health as you recover from long COVID. These recommendations can help your body rest and give it the opportunity to heal:

• Eat well-balanced and healthy meals.
• Exercise if you can tolerate it. Ask your doctor what is right for you.
• Avoid alcohol, drugs, and smoking.
• Get plenty of rest.
• Stretch, meditate, or practice mindfulness.

Deep breathing exercises (including yawning and humming) can also help restore lung function and air capacity while strengthening the diaphragm. These are especially important if you were hospitalized with COVID-19, because inactivity in the hospital can negatively affect the lungs.

Ask your doctor which exercises and treatments might help you recover from long COVID lung symptoms.

Talk With Others Who Understand

On myCOVIDteam, the social support network for those recovering from the effects of COVID-19, you can connect with others. Members come together to ask questions, give advice, and share their stories with others who understand.

Have you experienced breathing issues due to long COVID? What has helped you breathe easier? Share your insights in the comments below, or start a conversation by posting on myCOVIDteam.