It might not qualify as a serious danger per se, but rough handling can quickly sour any spa experience. People visit spas to relax, not because they have a hankering to be used as a human punching bag. If a massage is too vigorous for your liking, just ask the massage therapist to take it easy. And while some people like to chat while they're getting spa services, others prefer relaxing in silence. That's why it can be important to find a professional who's willing to be flexible and do the things that will help you get the most out of your session -- especially if it's pricey.
Pushy practitioners can also make spa visitors feel pressured to shell out lots of cash for various products after a treatment. Following an hour of gentle relaxation, this sort of doggedness can be most unwelcome; do a little research and ask around to make sure you won't find yourself right back to stressed-out after what was supposed to be a relaxing day at the spa.