Coughing long after testing positive for COVID-19? You’re not alone: Take one scroll through the #covidcough hashtag on Twitter, and you’ll see many people complaining of gnarly coughs that won’t go away—sometimes with no other symptoms and for weeks to months after their initial infection. While a lingering cough can sometimes be a sign of long COVID, in many cases, it is just part of the normal recovery process that occurs after any viral infection.
“Prolonged cough after illness is not unique to COVID,” Nathaniel Marchetti, DO, the medical director of the respiratory intensive care unit at Temple University Hospital, tells SELF. Here’s what you need to know about why COVID-19 can cause a lingering cough and how long it might take to for this frustrating symptom to ease up.
Why does COVID cause such a nasty cough in the first place?
A cough is a protective mechanism to keep mucus or foreign objects out of the lungs. With COVID and other viral infections, the cause is irritation to the airways. “The virus gets into the cells in the airways and causes inflammation,” Dr. Marchetti explains.
There are two types of cough: wet (or productive) cough and dry cough. Dry cough is usually caused by a viral infection, says Dr. Marchetti. A wet cough involves coughing up mucus and may involve a bacterial infection. Dry cough is one of the most common COVID symptoms, although it’s possible to have a wet cough with COVID, too.
Doctors don’t know why some people get a nasty cough with COVID, while others don’t cough at all. “There is much we do not understand about COVID-19, including why some people have persistent symptoms,” Denyse Dawn Lutchmansingh, MD, the associate director of the Winchester Center for Lung Disease and the associate director of the Post-COVID-19 Recovery Program at Yale University School of Medicine, tells SELF.
Anecdotally, BA.5—the dominant omicron subvariant fueling the recent rise in cases in the U.S.—seems to be linked to cough more than previous strains. While it’s too soon to have concrete data on this, “experience by my colleagues suggests that, at least in the acute phase, these BA strains do seem to be more upper airway and cough associated,” Frank Sciurba, MD, a professor of medicine at the University of Pittsburgh School of Medicine and a member of the pulmonary committee of the National Institutes of Health RECOVER long COVID clinical trial, tells SELF.
How long does a COVID cough last?
Most coughs clear up in about two to three weeks, per the U.S. National Library of Medicine. A nagging, dry “post-viral cough” can last up to eight weeks, as inflammation in the airways persists even though a person is no longer infected with a virus. A productive cough that lasts longer than four weeks, however, may involve a bacterial infection, Dr. Lutchmansingh says.
Dr. Scuirba also points to a 2021 review of research that explored 57 studies including more than 250,000 people living with long COVID. The paper concluded that about 13% of people have a cough that lasts at least one month after a previous COVID infection. Cough from any cause is only considered chronic when it persists for more than eight weeks in adults, says Dr. Sciurba.
Why can a cough linger beyond other symptoms?
COVID may be more likely than other viruses to cause a chronic cough because it affects so many different systems in the body, says Dr. Marchetti. Some research suggests that COVID may impact the neural pathways in your brain associated with cough. Known as a neurogenic cough, “this basically means the nerves that are responsible for initiating a cough or creating a cough no longer function in the way they should, causing coughing to occur at inappropriate times,” Dr. Lutchmansingh explains.