Physical Danger
Don't make this face too often...it might get stuck that way.
If your goal is to play a sport that involves savagely beating your opponents into a bloody pulp by hitting them repeatedly with your own body, tennis is probably not your best bet.
If, on the other hand, you're looking for a relatively safe, non-contact sport that involves using your superior mental toughness to mercilessly demoralize your opponents, you've come to the right place. Basically, if tennis were a Hogwarts house, it would be Ravenclaw.
What we're trying to say is that tennis is pretty safe. Well, unless you're playing against Mr. Deeds.
You're not going to see the gruesome contact injuries you might encounter in a sport like football. That being said, because tennis is such a physically strenuous sport, what with all the running and jumping and sliding and pounding on a hard surface, athletes are susceptible to an array of strains, pulls, and tears.
You may have also heard of tennis elbow. People who don't even play tennis sometimes get tennis elbow. It's basically just tendonitis, or an inflammation of the tendons in your elbow. It can come from overuse, like all that swinging you're constantly doing. To avoid these sorts of injuries, it's crucial to take the time to stretch and rest adequately. And remember: good form is your BFF.