But a recent study points to a new avenue of research - it found that chronic cough may be hereditary.
The type of cough also seems to be important. It has been found that parents often pass on the same cough to their children, either a non-productive (dry) cough or a productive cough in which mucus or phlegm is secreted.
It is unclear which genetic and environmental conditions contribute to coughs continuing to be passed down through generations, although analysis of the human genome is currently underway, according to the international team behind the study published in October.
"These results suggest that there is a genetic link to chronic cough. This could provide a better understanding of the onset of chronic cough, which could ultimately lead to better treatments for this difficult-to-treat condition," said medical scientist Esur Ingi Emilsson of Uppsala University in Sweden.
Emilsson and his colleagues analysed data on 7155 parents and 8 176 young people (aged over 20) in northern Europe. In families where one parent had a chronic, non-productive cough, 11% of the children also developed the same cough.
In comparison, in the absence of chronic, non-productive cough in the parents, 7% of the children had this type of cough. Put another way, if a parent had a non-productive cough, their child's likelihood of having one increased by just over 50%.
The team accounted for various factors such as gender, asthma and smoking and the association still held.
The same was found for productive cough, although here the other factors reduced the statistical significance.
"A similar association was seen in productive cough, but in these cases smoking had a greater influence on prevalence," says Emilsson.
Already, a treatment study has been launched to further the problem: researchers hope to identify specific genetic variants associated with chronic cough that could potentially be targeted by therapeutic drugs.
A cough you can't get rid of significantly impairs a person's quality of life and is associated with the need to take significantly more sick days from work.
Understanding the role that genetics plays in the development of cough will be important in efforts to ensure that fewer people develop this disease in the future.
In another study, a team including some of the same researchers looked at data from 62,963 adults in Sweden, finding that between 2016 and 2018, only 1-2% of the population sought help for a chronic cough - most of them women aged between 40 and 70.
"It was unexpected to me that only 1-2% of patients sought help for a nagging cough when over 10% were affected. This can be partly explained by the lack of effective treatments," says Emilsson. | BGNES
