What Causes Shortness of Breath?

Feeling breathless can be frightening. Shortness of breath or dyspnea is characterized by tightening in the chest and difficulty breathing. You may feel suffocated or need rapid breaths. You might also feel as if you aren’t getting enough air. Though it occurs in healthy individuals under certain conditions, it can also signal an underlying medical condition. 

What Is Shortness of Breath?

Shortness of breath is a medical condition where normal breathing becomes difficult, sometimes described as “air hunger.” The heart and lungs transport oxygen within the body and remove carbon dioxide. Any disorder in this process affects normal breathing and can make you feel short of breath. It can also indicate a more severe heart or lung condition. Breathlessness can occur suddenly for short periods (acute) or last longer (chronic).

What Causes Shortness of Breath?

Healthy individuals can experience breathlessness at high temperatures or altitudes, after strenuous exercise or due to obesity. It can also occur due to anxiety or a panic attack. However, if the condition occurs suddenly or persists for a prolonged period, it signals an underlying health problem.

Shortness of breath or dyspnea can either be acute or chronic.

Acute Shortness of Breath

Acute dyspnea begins within a short period. You may also have symptoms like fever, rash or cough. Some of its causes include:

• Anaphylaxis is a potentially dangerous allergic reaction that occurs shortly after exposure to the allergen. It constricts the airways, causing breathlessness.
• Asthma is an inflammatory response that causes your airways to become narrow and swell (may sometimes produce extra mucus). These narrow airways hinder normal breathing.
• Heart problems. The heart pumps and circulates oxygenated blood throughout the body. Any variation in this rhythmic process impacts breathing. Heart attack, heart failure, arrhythmia (change in heart rhythm) and cardiac tamponade(blood/fluid build-up around the heart) can affect normal breathing. 
• Lung problems. Lungs oxygenate the blood and remove carbon dioxide. Its proper functioning ensures optimum delivery of oxygen throughout the body. Decreased oxygen levels in the blood can make you feel breathless. It can arise due to  Pneumonia, pneumothorax (air leaks into the space around the lungs) and pulmonary embolism (blockage in one of the pulmonary arteries). 
• COVID-19. Coronavirus attacks the respiratory system in humans and causes inflammation. This inflammation of the lungs affects its oxygen exchange and makes breathing difficult.
• Carbon monoxide poisoning. One of the symptoms of carbon monoxide poisoning is shortness of breath. It occurs when the inhaled air has a high concentration of CO. The body replaces oxygen with carbon monoxide in the red blood cells. As a result, severe tissue damage and even death occur.

Chronic Shortness of Breath

Chronic dyspnea persists for an extended period. It interferes with your day-to-day activities like walking or standing. Its causes include:

• Asthma
• COPD (Chronic obstructive pulmonary disease) causes trouble breathing. It restricts the flow of air from the lungs. Prolonged exposure to irritants like cigarette smoke damages the lungs and airways and leads to COPD. 
• Heart dysfunction or heart failure is a condition that arises when the heart doesn't function properly. It can occur either because the heart cannot fill up with blood or is too weak to pump blood. As a result, the blood pressure increases, causing fluid build-up in the lungs, making breathing difficult.
• Obesity is a condition of excess fat accumulating in the body. Excess fat on the neck, chest or abdomen can lead to obesity hypoventilation, characterized by shallow or too slow breathing. Hypoventilation decreases the oxygen level, causing breathlessness.        
• Interstitial lung disease (ILD) is a group of lung disorders that causes inflammation and fibrosis(damaged lung tissue). It can decrease the efficiency of the lungs and make you feel short of breath.
• Pleural effusion (fluid around the lungs) arises when fluid builds up in the space (pleura layers) between the lungs and the chest wall. Many conditions can lead to pleural infusion. The fluid around the lungs makes it difficult to breathe.

Miscellaneous Causes for Shortness of Breath

Besides acute and chronic dyspnea, some cases of shortness of breath are temporary. Their causes include:

• Disruption of the airway (choking)
• Anemia
• Broken ribs
• Anxiety
• Epiglottitis is the swelling of the epiglottis. Epiglottis is a flap of tissue that prevents food from entering the trachea(windpipe). An infection or inflammation of the epiglottis can obstruct the windpipe and make breathing difficult. 
• Guillain-Barre syndrome is a rare autoimmune disorder in which the body attacks its nerves. The nerves control the body's movements and functions. Hence, this disorder interferes with normal breathing.
• Kyphoscoliosis (abnormal curve of the spine) 
• Myasthenic crisis (weakness and rapid fatigue of the lung muscles)

Diagnosing a medical condition is the first step towards treatment. Shortness of breath can arise due to various underlying conditions. It is important to find the root cause of the problem before deciding the treatment. If you experience difficulty in breathing or feel out of breath, don not delay to consult a doctor. An early diagnosis can ease your symptoms and prevent other complications.