A weak handshake could be an early sign of a failing heart, scientists say.
An association has been found between a limp grip and unwelcome changes in heart structure and function.
Experts believe hand grip could be used as a broad measure of heart health.
Researchers analysed heart scan images from almost 5,000 study participants, including people with floppy and vice-like handshakes.
They found that a stronger grip was associated with higher volumes of blood being pumped by the heart and healthier heart muscle.
This in turn led to a lower risk of cardiovascular events such as heart attacks and strokes.
People with weak handshakes were more likely to have enlarged, damaged hearts.
Professor Steffen Petersen, who led the team from Queen Mary University of London, said: "Our study shows that better hand grip strength is associated with having a healthier heart structure and function.
"Hand grip strength is an inexpensive, reproducible and easy to implement measure, and could become an easy way of identifying people at high risk of heart disease and preventing major life-changing events, such as heart attacks."
For the study, hand grip strength was measured by asking people to grasp a device called a dynamometer for three seconds.
The findings appear in the journal Public Library of Science ONE.
Julie Ward, from the British Heart Foundation, which co-funded the research, said: "It's important to keep in mind that this research does not mean you will have a heart attack if you find yourself with a limp handshake or struggling to open a jar. If you are concerned about your heart health, or your overall fitness, please speak to your GP."
Heart disease kills 66,000 people each year in the UK, mostly as a result of heart attacks.