My car seized up this morning. So I had to catch the bus.
If something such as an engine seizes up, it stops working, because it has not been properly cared for. She put diesel fuel, instead of petrol, into the tank causing the motor to seize up
If a part of your body seizes up, it suddenly stops working, because you have strained it or because you are getting old. We are all born flexible but as we grow older, we tend to seize up a little