A bad night's sleep is the worst. Not only are we grumpy and emotional the next day, but as it turns out, it actually puts a strain on our hearts.

A study by the University of Bonn in Germany has found a major side-effect of sleep deprivation: one night of poor sleep is all it takes for your heart to have to work 10 percent harder the next day.

Researchers studied 20 healthy radiologists who had their hearts pictured before and after a 24-hour shift. They also had their blood pressure taken, and gave blood and urine samples.

After each candidate's 24-hour shift (they each had about three hours of shut-eye during that time), the results revealed that their hearts were seriously strained and had to put in way more work than usual.

Their heart rate and blood pressure both increased the next day, and they also experienced a surge in the amount of thyroid hormones and cortisol (stress hormone) released.

The author of the study, Dr Daniel Kuetting told The Telegraph, "For the first time, we have shown that short-term sleep deprivation in the context of 24-hour shifts can lead to a significant increase in cardiac contractility, blood pressure and heart rate.

"The study was designed to investigate real-life work-related sleep deprivation. As people continue to work longer hours or work at more than one job to make ends meet, it is critical to investigate the detrimental effects of too much work and not enough sleep."

Do you think you get enough sleep each night?