Wheezing is a high-pitched, whistling sound that can occur when a person breathes, and it is a symptom many people associate with conditions like asthma. When someone contracts COVID-19, the infection primarily targets the respiratory system, leading to a range of breathing difficulties. Wheezing can indeed be a feature of a COVID-19 infection, although it is typically less common than other symptoms like a persistent cough or shortness of breath. This distinctive sound signals that the airways in the lungs have narrowed, obstructing the normal flow of air.
How COVID-19 Causes Wheezing
The SARS-CoV-2 virus, which causes COVID-19, primarily initiates an infection in the cells lining the respiratory tract. When the virus infects the respiratory epithelium, the body launches an inflammatory response to fight the pathogen. This immune reaction leads to an accumulation of inflammatory cells in the small airways, a process sometimes called bronchiolitis or bronchitis.
The resulting inflammation causes the walls of the bronchi and bronchioles to swell and thicken. This swelling, combined with muscle constriction around the airways (bronchospasm), significantly reduces the diameter of the air passages. The rapid movement of air through these narrowed tubes creates the high-frequency, whistling vibration heard as wheezing.
Identifying Wheezing Versus Other Respiratory Sounds
Accurately identifying wheezing is useful because it points to airway narrowing, distinguishing it from other common COVID-19 lung sounds. Wheezing is characterized by a continuous, musical, and high-pitched whistling sound, which is most often heard when exhaling. In more severe cases of airway obstruction, the wheeze may also be audible during inhalation.
Two other frequently heard abnormal sounds are crackles (also called rales) and rhonchi. Crackles are short, non-musical sounds that resemble a popping or bubbling noise, indicating the presence of fluid or collapsed air sacs (alveoli) deeper in the lungs. Rhonchi are lower-pitched, coarse gurgling sounds that suggest thick secretions or mucus are vibrating within the larger airways.
Interaction with Pre-Existing Conditions
Wheezing is significantly more likely to occur and be more severe in individuals who have a pre-existing chronic lower respiratory condition. For people with asthma, COVID-19 acts as an acute viral trigger, similar to the flu or common cold, causing a pronounced inflammatory response. The already hypersensitive airways of an asthma patient can react severely to the infection, leading to an asthma attack or a sharp increase in bronchospasm.
Chronic Obstructive Pulmonary Disease (COPD) also heightens the risk of respiratory complications, including severe wheezing. COPD involves permanent damage to the airways and air sacs, making the lungs less resilient to the acute inflammation caused by the virus. The combination of a chronic condition and the acute viral infection can lead to a rapid deterioration in breathing function. Patients with these conditions must continue their maintenance medications, such as inhaled corticosteroids and bronchodilators, to manage their underlying airway sensitivity and reduce the risk of a severe exacerbation during the COVID-19 illness.
Urgent Warning Signs
Wheezing can indicate a rapidly worsening condition that requires immediate medical attention. If the wheezing is accompanied by an inability to speak in full sentences, this suggests a severe shortage of breath. A rapid deterioration in symptoms, or a wheeze that does not improve after using a prescribed rescue inhaler, is an urgent sign of respiratory distress.
Other signs that necessitate calling emergency services include persistent pain or pressure in the chest and new confusion or an inability to wake up or stay awake. A bluish, pale, or grayish tinge to the lips, nail beds, or face, known as cyanosis, signals dangerously low oxygen levels in the blood. These symptoms show that the body is not receiving enough oxygen, meaning the airway obstruction is a medical emergency.