If you are about to undergo diagnostic ultrasound, it is important that you know it will be performed.
The technician will ask you to undress enough to expose the area where the test will be performed and to lie down on the bed. The technician will coat the transducer with conductive gel, which feels like lubricant jelly. If possible, depending on the tools and supplies available, the gel will be warm. Then the technician will slide the transducer over the skin, sometimes with firm pressure. Occasionally the pressure could cause some mild discomfort. Using the transducer to point to areas of interest, the technician will use the computer to capture images and might use a mouse to drag lines across the screen. The lines help measure size, like a virtual yardstick.
