Smokers and vapers who get Covid-19 are more likely to have complications, so this might be a good time to quit, the Society of Thoracic Surgeons says.
An early study from China looked at 78 hospitalised Covid-19 patients. Researchers found those with a history of smoking had 14 times the risk of needing a higher level of care, requiring a ventilator, and/or dying.
Covid-19 death rates in China are higher in men than in women, and higher smoking rates in men in that country may be a reason why.
"As Covid-19 is a virus that primarily attacks the lungs, anything that harms the lungs can weaken patients and result in more severe effects if people do become infected. It is well-known that smoking results in worse outcomes in people with pneumonia or influenza, and we are learning that smoking can pose significant risks in those with Covid-19," thoracic surgeon Dr Matthew Steliga wrote in a patient guide from the society.
Electronic cigarettes aren't any safer
He pointed out that smoking thickens the mucus lining people's airways, making it harder to clear away inhaled fungi, bacteria and viruses.
"This leads to more particles and infectious agents trapped in the lungs and more difficulty in clearing out this material," wrote Steliga, who practises at the University of Arkansas for Medical Sciences. "Those who smoke have a greater chance of getting respiratory infections, and when one does have an infection, it is harder to recover from it. Even an occasional cigarette or second-hand smoke has been linked to increased risks from acute respiratory distress syndrome."
And, he warned, electronic cigarettes aren't any safer than traditional cigarettes.
They can suppress immune function, and some research suggests that vaping impairs mucus clearance and the body's ability to fight infection, Steliga said.
"We do not have clear long-term data about e-cigarette use and Covid-19, but it is agreed that the best way to avoid complications from Covid-19 is to keep your lungs as clean and healthy as possible," he said in a society news release.