Shortness of breath is most often due to heart or lung conditions. The heart and lungs help move oxygen to your body and get rid of carbon dioxide. Trouble with either of these processes can make breathing hard.

Sudden shortness of breath

Shortness of breath that comes on suddenly, also called acute shortness of breath, may be caused by these conditions or others:

1. Anaphylaxis
2. Asthma
3. Blocked airways.
4. Blood loss that happens suddenly.
5. Carbon monoxide poisoning
6. COPD
7. Coronavirus disease 2019 (COVID-19)
8. Fluid buildup around the heart, called cardiac tamponade.
9. Heart attack
10. Heart arrhythmia
11. Heart failure
12. Pneumonia and other lung infections.
13. Pneumothorax — a collapsed lung
14. Pulmonary embolism — a blood clot in an artery in the lung

Long-term shortness of breath

Shortness of breath that lasts for weeks or longer, also called chronic shortness of breath, may be due to:

1. Asthma
2. COPD
3. Fluid buildup around the lungs, called pleural effusion.
4. Heart problems.
5. Interstitial lung disease and other lung diseases.
6. Obesity
7. Weak muscles from not being active.

Many other health conditions also can make it hard to breathe. These include mental health conditions, lung conditions, heart conditions and other medical conditions.

Mental health conditions

Examples include:

1. Anxiety disorders
2. Panic attacks and panic disorder
3. Stress.

Lung conditions

Examples include:

1. Croup — especially in young children.
2. Lung cancer
3. Pleurisy
4. Pulmonary edema — too much fluid in the lungs
5. Pulmonary fibrosis
6. Pulmonary hypertension
7. Sarcoidosis
8. Tuberculosis

Heart conditions

Examples include:

1. Cardiomyopathy
2. Heart failure
3. Pericarditis

Other medical conditions

Examples include:

1. Anemia — a condition in which the body doesn't get oxygen due to a lack of healthy red blood cells
2. Broken ribs
3. Choking: First aid
4. Epiglottitis
5. Foreign object inhaled: First aid
6. Guillain-Barre syndrome — a condition in which the body's immune system attacks the nerves
7. Hay fever — also called allergic rhinitis.
8. Kyphoscoliosis, a complex curving of the spine.
9. Myasthenia gravis — a condition that weakens the muscles you control
10. Nasal polyps or anything else that causes a blockage or trouble breathing through the nose, such as congestion or injury.