As respiratory illnesses surge across the country, the persistence of a cough that just won’t quit may be prompting some to wonder if there is a deeper underlying issue.
This lingering cough is what Nicholas Vozoris, an assistant professor and staff respirologist at Saint Michael’s Hospital, University of Toronto, calls a “post-infectious cough” and it can last as long as eight weeks.
“This is a cough that seems to linger after the other infectious symptoms settle down,” he said. “And this post-infectious cough is known to possibly occur with viral or bacterial respiratory tract infections.”
While doctors like Vozoris have long been familiar with post-infectious cough as a condition, he believes it may not be widely recognized by the public.
He noted that many patients are often surprised when hearing about this diagnosis. But it’s very common during cold and flu season, and Canada is currently in the thick of it.
The latest available Health Canada data shows a slight decrease in reported influenza infections from Dec. 31 to Jan. 6 compared to the previous weeks. However, Health Canada said cases “remain at elevated levels.”
Vozoris acknowledges that a lot of people are suffering from the lingering cough and may be worried about whether to see a doctor or not.
“It can be annoying, but usually it’s not concerning. It typically peters out on its own with time without other interventions. Usually what’s done for post-infection is just reassurance and waiting,” he said.
However, there are times when a lingering cough could be a result of another underlying medical condition or respiratory issue, Vozoris cautioned.
What causes a post-infectious cough?
Coughing, with or without phlegm, represents a common symptom of respiratory tract infections, Vozoris explained. It’s a natural way to expel infectious bacteria or viruses from the body, and then restrict their spread within the respiratory system.
Dr. Brian Conway, medical director of the Vancouver Infectious Disease Centre, says sometimes an infection can irritate the airways and make you cough more.
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“The airways may remain overactive for days, weeks, months and may require specific interventions,” he said, adding it may lead to long-lasting discomfort and ongoing coughing. This is the point at which it transitions into a post-infectious cough – the infection has resolved, but the cough persists.
And if you notice your cough tends to get worse at night or in the early morning, rest assured that you’re not imagining it.
Coughing often worsens at night, Vozoris said, because when you are lying down it can cause accumulation of mucus and facilitate postnasal drip.
“Also, when you’re sleeping at night, you are not coughing periodically and clearing mucus. It can build up, and then you may wake up at night or in the morning and need to do a lot of mucus clearing because it’s built up in the airways at night from sleep,” he explained.
Should you be worried about a lingering cough?
While many instances of post-infectious coughs may not be a cause for concern, Vozoris mentioned that some instances could involve more troubling symptoms.
“If one is having protracted coughing, it’s probably a good idea to get that evaluated, and to get guidance on whether this is a post-infectious cough versus something else,” he cautioned.
The lingering cough may be the emergence of a chronic respiratory disease as a result of the infection, he explained. For instance, conditions like asthma may arise following a respiratory tract infection.
Another reason could be chronic bacterial sinusitis, which is long-term inflammation of the sinuses, usually lasting for around 12 weeks.
“This could be contributing to ongoing cough from secretions that are dripping down the airway,” Vozoris said.
That’s why he emphasized the importance of consulting a health-care provider if you have concerns about your persistent cough.
“A health-care professional can tease it out. Does this seem to be just post-infectious cough versus has asthma emerged? Was this an atypical infection? Do you have chronic bacterial sinusitis? And that stuff can get teased out with asking questions examining the patient and getting some relevant testing,” Vozoris said.
What about whooping cough?
Whooping cough, also known as pertussis, is a highly contagious respiratory infection, which may also be a factor contributing to a lingering cough, Vozoris warned.
The bacteria that cause whooping cough spreads easily from person to person through the air. When a person who has whooping cough sneezes or coughs, they can release small particles with the bacteria in them, according to the U.S. Centers for Disease Control and Prevention (CDC).
This is the sickness that is typically known as the “100-day cough,” he added.
However, because Canadians get vaccinated against whooping cough in childhood and pregnancy, he doesn’t believe this infection is as prevalent in the country.
But “it could be a possibility.”
Can a post-infectious cough be treated?
A post-infectious cough can be disruptive, especially in the evening if it interrupts your sleep. To help treat it, Conway said it’s a matter of helping reduce irritation in the throat.
“It may not be your airways or down into your lungs. It may just be that your throat remains red, raw, and irritated, so anything that would soothe it is helpful,” he said, adding that hydration is key.
He also suggested that honey and lozenges can be effective in soothing an irritated throat caused by excessive coughing.
In other cases, Vozoris said, a physician may prescribe a bronchodilator or a puffer that may provide some relief.
“Sometimes one could consider prescribing a very low-dose steroid pill,” Vozoris added. “But in general, what’s done is reassuring people they just need to be a bit patient.”
