[have a fit] or [have fits] or [throw a fit] {v. phr.}
1. To have a sudden illness with stiffness or jerking of the body.
* /Our dog had a fit yesterday./
2. {informal} To become angry or upset.
* /Father will throw a fit when he sees the dent in the car./* /Howard will have a fit when he learns that he lost the election./* /When John decided to drop out of college, his parents had fits./