Turns out that pesky cough may last longer than you think. According to new research, the average length of a cough is nearly 18 days.

“There is a mismatch in what people believe and reality,” says researcher Mark H. Ebell of the University of Georgia in Athens.

“If someone gets acute bronchitis and isn’t better after four to five days, they may think they need to see a doctor and get an antibiotic.”

In the study, published online in the journal Annals of Family Medicine, Ebell performed a meta-analysis by looking at 19 observational studies that took place in the US, Europe, Russia and Kenya.

He used the placebo or untreated control groups to determine that acute cough illness actually lasts an average of 17.8 days.

Researchers then asked 500 adults via a telephone survey how long a cough should last in different situations, such as with a fever or without. Most people expected an illness to last only seven to nine days.

When a cough lingers longer than people expect, they also wind up taking antiobiotics, which Ebell says is a big problem in that prescription antibiotics do nothing for viral infections yet overprescribing the drugs can increase antibiotic resistance.

According to the US Centers for Disease Control and Prevention, acute cough illness accounts for two to three per cent of visits to outpatient physicians. Over half of these patients leave with a prescription for antibiotics.

Still, WebMD cites some red flags that may signal your nagging cough is more serious. If your cough is accompanied by fever, body aches, shortness of breath, wheezing, or hoarseness, talk to your doctor. — AFP RELAXNEWS