- Natasha Yates
- The Conversation*
Cough is a socially awkward symptom, especially since the Covid-19 pandemic began.
The problem is that the cough can persist for weeks or months after the infection is gone. About 2.5% of people continue to cough a year after being infected with Covid.
A recurring cough can hamper your ability to work, leave you with medical bills to pay, and lead you to avoid social engagements because, after all, you don’t want others to be afraid that you’re spreading covid.
As a general practitioner, I hear patients ask me if there is anything that can correct their post-covid cough. Next, I share my answer.
What causes coughing during covid?
It is not surprising that covid causes coughing, because the virus affects our respiratory tract, from the nasal passages to the lungs.
Coughing is one of the body’s ways of getting rid of unwanted stuff like viruses, dust and mucus. When something “foreign” is detected in the respiratory tract, a reflex is triggered to cause coughing, which should get rid of this irritating particle.
While this is an effective protection mechanism, it is also the way the Covid virus spreads. This is one of the reasons the virus has traveled so effectively and quickly around the world.
why the cough persists after the infectious period?
Inflammation is a defensive process that our immune system uses to fight Covid. Inflamed tissues swell and produce fluid. This can last a long time, even after the virus is gone.
Cough can persist for any of four main reasons, all of which involve inflammation:
1.If the upper airways (nasal and sinus) become inflamed, the fluid produced runs down the back of the throat causing a “postnasal drip”. This makes you feel the need to “clear your throat”, swallow and/or cough;
2. If the lungs and lower airways are affected, coughing is the body’s way of trying to clear the fluid and swelling it feels there. Sometimes there is not much fluid (so the cough is “dry”), but swelling of the lung tissue still triggers the cough;
3. There may be neural pathways to be where the inflammation is located. This means that the nervous system is involved, centrally (the brain) and/or peripherally (nerves), and the cough is not primarily from the respiratory tissues themselves;
4. A less common but more serious cause may be lung tissue being scarred by inflammation, a condition called “interstitial lung disease”. This needs to be diagnosed and managed by respiratory specialists.
Interestingly, people can experience a range of post-covid symptoms, including coughing, regardless of whether they are sick enough to be hospitalized. Some patients tell me they weren’t particularly bad during the covid infection, but the post-infectious cough is driving them crazy.
When should I seek medical help?
We need to be careful not to associate a cough with a post-covid cough and miss other serious causes of chronic cough.
One thing to watch out for is a secondary bacterial infection in addition to covid. Signs that you may have a secondary infection include:
– A change in the type of cough (sounds different, more frequent)
– Change in sputum/phlegm (increased volume, presence of blood)
– Developing new symptoms, such as fever, chest pain, racing heart, or worsening shortness of breath.
Other potentially serious illnesses can cause chronic coughing, including heart failure and lung cancer; therefore, if you have any doubts about the cause of the cough, seek medical help.
What is the evidence on ways to improve coughing?
If the cough is primarily a postnasal drip, she will respond to measures to reduce it, such as sucking on lozenges, saline solutions, nasal sprays, and sleeping upright.
Some people may develop cough hypersensitivity where the cough reflex threshold has been lowered so it takes much less to trigger a cough. It’s a common response to colds and it can take a while for our bodies to “reset” themselves to a less sensitive state.
If a dry or ticklish throat triggers the cough reflex, solutions include drinking water slowly, eating or drinking honey, and breathing slowly through your nose.
When breathing slowly through the nose, the air reaching the back of the throat is warmed and hydrated by first passing through the nasal cavities. Your cough reflex is therefore less likely to be triggered and over time the hypersensitivity should resolve.
If the cause stems from inflammation in the lungs, controlled breathing exercises and inhaling steam (in a hot bath or through a vaporizer) can help.
Thick mucus can also be made thinner by inhaling saline through a nebulizer, which turns the liquid into vapor and delivers it directly to the mucus that accumulates in the lungs. This helps to get rid of coughing.
Are there other options?
Budesonide (inhaled steroid), when given soon after a diagnosis of covid, has been shown to reduce the likelihood of needing urgent medical care, as well as improve recovery time.
Unfortunately, there are no good tests on the use of budesonide inhalers for post-covid cough.
However, in specific situations, they have helped some patients with post-covid cough when nothing else helps.
Experiments with steroid pills to treat a post-covid cough are still ongoing and are not recommended unless they are shown to result in significant improvement.
Antibiotics won’t help
It is worrying that some countries have guidelines that indicate the use of antibiotics to treat covid, showing how prevalent this misunderstanding is.
Unless there is a secondary bacterial infection, antibiotics are not appropriate and can contribute to the development of resistance to them.
Post-covid cough can last for weeks, be debilitating and have a variety of causes. Most ways to manage it are simple, inexpensive, and can be done without the need for medical intervention.
However, if you have any doubts about the cause or progression of your cough, it’s worth a visit to your GP to check.
*Natasha Yates is a general practitioner and professor at Bond University in the United States
This article was originally published on the academic news site The Conversation and republished under a Creative Commons license. Read the original version here (in English).
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