A US study suggests that people, who sleep less than 7hrs a night, have a higher risk of getting a cold.

The researchers from Carnegie Mellon University noticed that people with less than 7hrs sleep had three times higher risk of catching cold than those who took 8 or more hours sleep every night.

Experts believe that the human immune system impairs because of less sleep, and the body doesn’t remain capable enough to fight against those viruses that become the cause of cold and flu.

The study has been published in the Achieves of Internal Medicine online issue.

The results of some previous studies suggest that people, who take seven or eight hours sleep every night, have significantly lower risk for heart disease.

But still, there is little evidence which show that good night sleep can be helpful to avoid a cold or flu.

In their study the researchers inquired about the sleeping habits of 153 healthy men and women whose average age was 37 years. The participants of the study were quarantined then and they were given rhinovirus nasal drops that become the cause of common cold.

The participants were asked to report if the had any sign of illness. Their mucus samples of nasal passages were also collected.

The researchers found that people who slept less had higher chances of developing a cold. According to the researchers, regulations of some basic chemicals that are produced by immune system get disturbed because lack of sleep and immune system can’t fight effectively against infection.