Physical Danger
Worst-case scenario: you slip and fall on some of that ultrasound jelly and end up in the hospital. But, let's be honest, you're probably already in a hospital. Also, the likelihood of that happening is pretty slim (knock on wood). It's very unlikely that you'll find yourself in an extreme physical danger as an ultrasound technician.
Just because you aren't jumping through rings of fire doesn't mean you can't get hurt over the long term, though. Ultrasound technicians spend a lot of time on their feet, bent over equipment and patients doing repetitive motions while scanning.
They also do some heavy lifting as they assist patients on and off the ultrasound chair. We're not trying to be rude or anything, but people are generally pretty weighty, especially if they're a lot bigger than you.
Standing up a lot plus repetitive motions plus heavy lifting can add up to a whole lot of ouch, particularly in your joints and back (source). We suggest grabbing a pair of those ugly orthopedic shoes and start rocking the "hospital staff" look. Everybody's doing it.