Lingering cough? When you should go to the doctor for a cough that won't go away, according to an expert

A cough after a cold, the flu or COVID can last anywhere from three to eight weeks, according to an expert.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

What should you do to treat a lingering cough? We asked an expert. (Image via Getty Images)
What should you do to treat a lingering cough? We asked an expert. (Image via Getty Images)

In a post-pandemic world, heightened awareness of respiratory symptoms has become pretty common. Although once dismissed as commonplace, coughs may now trigger concerns due to the residual effects of the recent global health crisis — even if they’re nothing to be worried about.

Lingering, nagging or post-infectious coughs can occur for many reasons and can last anywhere between three to eight weeks. According to a new article published in the Canadian Medical Association Journal (CMAJ), approximately 11 to 25 per cent of adults will experience a cough after experiencing a cold, the flu or COVID, and while they can be annoying at best, physicians say coughs like these mostly just need to be waited out.

“We see this probably every fall and winter from the most common thing — the common cold,” Dr. Nicholas Pimlott, academic family physician at Women’s College Hospital, tells Yahoo Canada.

Thanks in part to COVID, Pimlott says many fear that a lingering cough means they’re still contagious or if there’s something else at play.

So how do you treat this frustrating post-cold symptom and when should you see a doctor? Here’s what you need to know.

What causes a lingering cough?

Subacute coughs can last for three to eight weeks . (Image via Getty Images)
Subacute coughs can last for three to eight weeks . (Image via Getty Images)

Coughing is a natural reflex designed to clear the airways of irritants and mucus. When it lingers after other symptoms disappear, this is actually a sign of the “inflammatory cascade” phase, the CMAJ article explains.

Pimlott says "residual inflammation"and increased bronchial sensitivity and mucus production can a continuous cough. However, there are things outside of a common cold that can cause a lingering cough, like asthma or acid reflux, he says. When patients come in to see him, he takes the time to rule out these options before moving forward.

Identifying what type of cough the patient has helps, too. While historically physicians have divided types of coughs into two categories, acute (short-term) and chronic (lasting more than eight weeks), a third category has been introduced to include subacute coughs that last three to eight weeks. These kinds of coughs are usually not serious and simply caused by prior infection, leading to inflammation that goes away on its own.

When should you see your doctor about a cough?

Time is one of the most important factors when deciding whether you should head to a walk-in clinic or visit your doctor’s office. While the numbers are arbitrary, Pimlott explains, it's worth seeing a physician if the cough persists for more than three weeks, but all other symptoms have resolved.

“Even if there’s nothing more worrisome going on than some residual airway irritation, we can treat it,” he says. “We can relieve people of the symptom of coughing because it’s a nuisance.” Disrupted sleep, muscle strain and even fractured ribs (although rare) can occur because of a persistent cough.

When should you visit a doctor for a cough? (Image via Getty Images)
When should you visit a doctor for a cough? (Image via Getty Images)

The most common treatment is a trial of a decongestant antihistamine, which helps clear out the sinuses, reduce production of mucus and get rid of the cough. But what about over-the-counter options?

“If you go into any pharmacy, there’s shelves lined with remedies for coughs and colds,” he says. “We generally think that they’re not that effective.”

While there’s no danger in trying them, research cited in the CMAJ article shows that most trials found cough symptoms improved without medication, even antibiotics or inhalers — a finding that may be frustrating for the everyday person trying to treat themselves.

So how do you know when a cough is more than just a cough? While many resolve themselves with time and patience, “we look for red flags that suggest there’s something worrying going on,” Pimlott says. If you’re experiencing other symptoms like coughing up blood or coloured mucus, shortness of breath, wheezing, fever, chills or night sweats, it’s definitely time to take yourself to the doctor.

How can you treat a lingering cough at home?

A humidifier and hot shower can help ease a nagging cough. (Image via Getty Images)
A humidifier and hot shower can help ease a nagging cough. (Image via Getty Images)

If your post-infection cough just won’t let up and isn’t combined with other worrying symptoms, there are some easy at-home tricks to help reduce the effects:

  • Humidifier: Use a humidifier to add moisture to the air, which can help alleviate irritation in the throat and respiratory passages.

  • Get steamy: Warm air can improve a phlegmy cough. Take a hot shower or bath, or lean your head over a bowl of hot water and breathe in for 10 to 15 minutes.

  • Lots of hydration: Drink plenty of water, herbal teas and clear broths to stay hydrated and soothe the throat.

  • Honey in tea: A 2021 study shows that honey helps suppress coughs and prevent the need for other medications.

  • Cough drops: While cough drops don’t heal a cough, they do help wet a dry throat and put a damper on a nagging cough for a bit.

While these tactics can help with some of the symptoms of a run-of-the-mill cough, time is ultimately what does the trick, Pimlott says.

“It’s a matter of waiting it out and letting the body heal itself.”

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