The general consensus among health experts is that any form of smoking or inhalation is detrimental during an active COVID-19 illness. When the body is fighting a respiratory infection, introducing smoke or aerosol into the lungs directly interferes with the natural healing process. The respiratory system is already under immense stress from the virus, and adding chemical irritants can immediately worsen symptoms and increase the chance of disease progression.
Smoking’s Immediate Effect on Acute Symptoms
Smoking during an active COVID-19 infection immediately exacerbates physical discomfort and compromises the body’s localized defenses. Smoke or hot aerosol causes direct irritation to the delicate lining of the airways, which are already inflamed from the viral attack. This irritation often increases the frequency and severity of coughing, as the body attempts to clear the compromised airways. Furthermore, inhaling smoke deposits carbon monoxide, which reduces the blood’s oxygen-carrying capacity when the lungs are already struggling to maintain adequate oxygen saturation.
A primary mechanism of harm involves ciliary function, the lung’s self-cleaning system. Cilia are tiny, hair-like projections that line the respiratory tract and sweep mucus and trapped pathogens out of the lungs. The chemicals in smoke can paralyze or damage these cilia, preventing them from performing this sweeping function effectively. This failure of mucociliary clearance leads to an accumulation of mucus and viral particles, allowing the infection to linger and intensify.
Elevated Risk of Severe COVID-19 Disease
Beyond the immediate worsening of symptoms, a history of smoking is a significant risk factor for developing severe COVID-19 disease. Smokers face a substantially higher risk of severe outcomes, including the need for mechanical ventilation, Intensive Care Unit admission, and death. For example, one meta-analysis found that current or past smoking was associated with a nearly two-fold higher mortality rate among hospitalized COVID-19 patients.
This increased vulnerability stems partly from pre-existing lung damage, such as chronic obstructive pulmonary disease (COPD) or emphysema, which compromises lung capacity and gas exchange. The viral infection then compounds this existing respiratory fragility. Smoking also compromises the immune system’s ability to mount an effective defense against the virus. Studies show that cigarette smoke can reduce the activity of interferons, which are primary components of the body’s early antiviral response.
Suppressing the interferon response effectively lowers the airways’ natural defenses, potentially allowing the SARS-CoV-2 virus to replicate more aggressively. The combination of structural lung damage and a weakened immune response means the infected smoker’s body is less equipped to fight the virus. This leads to a higher likelihood of rapid disease progression and severe outcomes.
Vaping, Cannabis, and Other Delivery Methods
The risks associated with traditional cigarettes extend to other inhaled substances, including e-cigarettes, vaporizers, and cannabis. Although the chemical composition differs, inhaling hot aerosol or smoke still causes significant irritation and inflammation in the already-stressed respiratory tract. Vaping delivers various flavorings and chemicals that can damage lung tissue and compromise immune function, making the lungs more susceptible to severe infection.
Smoking cannabis, like tobacco, introduces combustion byproducts and particulate matter deep into the lungs, contributing to airway inflammation and hindering clearance mechanisms. Furthermore, the psychoactive compound THC has been shown to suppress the immune system’s ability to respond effectively to pathogens. Because all inhaled products stress the lungs, the medical advice against smoking applies broadly to all delivery methods.
The social aspect of using inhaled products introduces an additional transmission risk. Sharing items like joints, pipes, or vaping devices creates a direct route for the coronavirus to pass between people. The frequent hand-to-mouth contact inherent in using these products also increases the chances of self-inoculation with the virus.
Medical Guidance for Abstinence During Infection
Healthcare providers strongly recommend immediate abstinence from all inhaled products upon COVID-19 diagnosis. Quitting smoking or vaping, even temporarily, removes chemical and thermal stress on the respiratory system. This allows the body’s natural defenses to function more effectively against the virus. Abstinence is advised until a person is fully recovered and all respiratory symptoms have resolved.
For those who rely on nicotine, medical professionals encourage using cessation resources to manage withdrawal symptoms during the infection period. Nicotine replacement therapies (NRTs), such as patches, gums, or lozenges, provide nicotine without the harmful byproducts of smoke or vapor. Utilizing NRTs helps the body focus on fighting the infection and mitigates cravings, making it easier to maintain abstinence.