Think you’re getting enough sleep? "I would say a third of my patients give themselves the opportunity to have the amount of sleep their body needs. The majority do not," says Dr. Cathy Risdon at McMaster University’s department of family medicine. Some factors that interfere with sleep are beyond our control, but a whole lot of them – the amount of time we set aside for rest, our activities before bed, our caffeine and alcohol intake – can be tweaked for better sleep. And that’s important.

"Sleep deprivation has a profound effect on most of the systems in our body," Dr. Risdon says. Most recently, a University of Pennsylvania study found that people who don’t sleep well may be more prone to obesity, diabetes and cardiovascular disease.

Are you getting all the sleep you need? Take our quiz.

1. When the alarm goes off in the morning: