Stress
Every job comes with stress; as an ultrasound technician, your stress level will depend on where you're stationed. If you work at a hospital, your day-to-day will be jam-packed and you'll often be on call. It will...kinda stink, to be honest. Being on call means having to sprint out of bed at 5:00AM with no advance warning.
Even if you're not running around in a hospital, working in a clinic is stressful, too. Whether you're working in the OB/GYN department, the neurology department, or the ophthalmology (a.k.a. eye disease) department, you'll be focused on one thing: early detection. Having to scour a patient's body to catch isty-bitsy little problems before they become big problems is a pretty big job. With big jobs come big stress.
If you do happen to find something while scanning, you'll have to worry about relaying that message to the patient—who's probably way more nervous than you. Scanning can be hard, but having good bedside manner when delivering any bad news can be even more stressful.