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A chronic cough is one lasting more than eight weeks. It is a symptom rather than a diagnosis. Day to day it can mean coughing most days, broken sleep, a sore chest, and feeling self-conscious in company.
Eight weeks is the dividing line. A cough after a chest infection can take weeks to fade, and that is normal. Past eight weeks, clinicians look for a driver: asthma, reflux, post-nasal drip, smoking or a medicine.
It is also not a dead end when tests come back normal. In a national Canadian survey, no underlying diagnosis had been identified in 44 percent of people with a long-lasting cough. That pattern has its own name: refractory or unexplained chronic cough. Researchers describe it as cough hypersensitivity, where the nerves that trigger coughing become over-responsive, so talking, laughing or cold air sets it off.
Canadian Respirology Today notes that people with refractory cough may cough a median of 500 times a day.
Some risk factors cannot be changed:
Others can often be worked on, usually with support from a health care team:
Most people start with a family doctor, and the Canadian survey found most were still managed in general practice. The assessment covers how long it has lasted, whether it is dry or productive, what sets it off, smoking and workplace exposures, and your medicines, with an examination of the chest, nose and throat. Respondents reported breathing tests, chest imaging, blood tests and allergy tests, which look for asthma, other lung conditions and allergy rather than diagnosing the cough itself. Where it continues, referral to a respirologist or a cough clinic follows, although only a minority in that survey had seen one.
Care starts by treating anything identifiable, then turns to the cough itself. A health care team may discuss:
There is no reliable way yet to predict which will suit a particular person. These are decisions for you and your own clinician.
Chronic cough is common in Canada and poorly served. In the national survey, no underlying diagnosis had been identified in 44 percent of people, more than half considered their treatment ineffective, 32 percent were on no treatment, and a third had stopped seeking care because nothing had worked. The medicines used were developed for other conditions, which is why Canadian Respirology Today describes P2X3 receptor antagonists such as gefapixant and camlipixant as emerging therapies still being studied. Other questions include how to measure cough reliably and who will respond to what.
Taking part is voluntary, informed consent comes first, you can stop at any time without affecting your regular care, and no one can say in advance whether a study will help you.
This page is written in plain language for people considering clinical research. It is general health information, not medical advice, and it does not replace a conversation with your own doctor or nurse practitioner.
More than eight weeks. Coughs that follow a cold or chest infection often take several weeks to fade, which is normal. Past eight weeks it is treated as a chronic cough and is worth investigating, because the causes and the treatments are different from those for a short-term cough.
This is common. In the Canadian national survey of people with refractory or unexplained chronic cough, no underlying diagnosis had been identified in 44 percent. Normal breathing tests and a clear chest x-ray rule out several conditions, but they do not explain a cough driven by over-responsive nerves in the airway. That pattern is a recognised problem with its own name, refractory or unexplained chronic cough, and its own developing treatments, not a sign that nothing is wrong.
Most chronic cough studies ask you to record your cough and its effects over several weeks, sometimes with a device that counts coughs, and to attend a small number of clinic visits. A research coordinator goes through the study in detail before you sign anything. Taking part is voluntary, you can withdraw at any time without affecting your regular care, and no one can say in advance whether a study will help you personally.
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