Breathing difficulty, clinically known as dyspnea, is a defining and often serious symptom of COVID-19. The SARS-CoV-2 virus primarily targets the respiratory system. Inflammation within the lungs can severely impair the body’s ability to take in oxygen. While many people experience mild illness, breathing trouble often signifies the infection has progressed into the lower airways.
The Mechanism of COVID-Related Breathing Difficulty
The SARS-CoV-2 virus initiates lung damage by binding to Angiotensin-Converting Enzyme 2 (ACE2) receptors found on lung cells. This viral invasion triggers a powerful inflammatory response as the immune system attempts to fight the infection. This results in widespread damage to the delicate air sacs, or alveoli, and the surrounding tissue.
The inflammation disrupts the alveolar-capillary barrier, which normally allows for efficient gas exchange. Fluid, debris, and inflammatory cells accumulate in the alveoli, a process known as alveolar flooding. This fluid buildup prevents oxygen from easily passing into the bloodstream and carbon dioxide from being expelled. This impairment in gas exchange, coupled with the stiffening of the lungs, leads to breathlessness.
In severe cases, this process can rapidly advance to viral pneumonia and Acute Respiratory Distress Syndrome (ARDS). ARDS is a form of progressive lung failure characterized by extensive diffuse alveolar damage and reduced lung compliance. The resulting mismatch between ventilation (air reaching the lungs) and perfusion (blood flow) causes profound hypoxemia, meaning dangerously low blood oxygen levels.
Recognizing Severe Breathing Trouble
Identifying when shortness of breath becomes an emergency is crucial for managing a COVID-19 infection at home. A key monitoring tool is a pulse oximeter, a device that clips onto a finger to measure blood oxygen saturation (\(\text{SpO}_2\)). A normal reading is 95% or higher; a reading consistently below 95% warrants calling a healthcare provider. An oxygen level consistently at or below 92% signals the need for immediate emergency medical care.
It is important to watch for physical signs indicating the body is struggling to get enough oxygen. These signs include a rapid or shallow respiratory rate; more than 30 breaths per minute suggests severe trouble. Other indicators of a medical emergency are a bluish tint to the lips, face, or nail beds (cyanosis). The inability to speak a full sentence without pausing to catch a breath, confusion, or a sudden change in mental alertness also requires immediate attention. A phenomenon called “silent hypoxia” can occur, where oxygen levels drop dangerously low without the person feeling acutely breathless, making pulse oximeter monitoring especially important.
Managing Shortness of Breath During Infection
For mild to moderate shortness of breath managed at home, techniques can help ease the feeling of breathlessness. Changing body positions helps the diaphragm, the main breathing muscle, work more effectively. Sitting upright and leaning slightly forward, or resting the head on a table, can ease the work of breathing. Lying on one’s stomach, known as prone positioning, can also improve air movement in the back sections of the lungs.
Breathing exercises, such as pursed-lips breathing, can help keep airways open longer, making the next breath easier. This technique involves breathing in slowly through the nose and then exhaling slowly through pursed lips, similar to blowing out a candle. In a hospital setting, management escalates to medical interventions like supplemental oxygen therapy to raise blood oxygen levels. For severe inflammation, medications such as corticosteroids may be administered to calm the body’s immune response. In the most severe cases of ARDS, mechanical ventilation is used to support breathing.
Persistent Breathing Issues After Recovery
For a significant number of people, breathing difficulties persist long after the initial COVID-19 infection has cleared, a condition known as Long COVID or Post-Acute Sequelae of COVID-19 (PASC). This lingering shortness of breath has several potential causes. One concern is the development of lung scarring, or pulmonary fibrosis, which is common after severe illness involving ARDS. This scar tissue stiffens the lung and permanently limits oxygen transfer into the blood.
Ongoing inflammation and damage to small blood vessels within the lungs may also contribute to chronic dyspnea. Some individuals develop conditions affecting overall body regulation, such as Postural Orthostatic Tachycardia Syndrome (POTS), causing heart rate and breathing changes upon standing. These long-term symptoms are often managed through pulmonary rehabilitation, which uses targeted breathing exercises and physical therapy to improve lung function and stamina. Persistent symptoms lasting three months or more should prompt discussion with a healthcare professional to identify the underlying cause and develop a management plan.