A new PLoS Medicine study says that people over the age of 50 who sleep five hours or less have a 30% higher risk of multiple illnesses than those who sleep seven hours.

The study examined whether sleep duration is associated with the incidence of first chronic disease, subsequent multimorbidity, and mortality over a 25-year period. 

Shorter sleep at 50 was also linked to a higher risk of death during the study period, primarily due to an increased risk of chronic disease.

Professor Derk-Jan Dijk, Director of the UK's Surrey Sleep Centre, said as quoted by BBC News that "this work reinforces that getting only short sleep is not good for us."

"Generally, it's not healthy – although, for some, it may be OK. The big question is why some people sleep less. What is causing it and is there anything we can do about it? Sleep is a modifiable lifestyle factor to a certain extent," he added.

Good-sleep tips

-Keep yourself busy and active during the day, but slow down before bedtime.

-Daytime naps should be avoided.

-Establish a good nighttime routine and make your bedroom relaxing and conducive to sleep - thick curtains or blackout blinds, a comfortable room temperature and bedding, and no major distractions, such as smartphone scrolling in bed.

-Caffeine should be reduced or eliminated near bedtime.