The flu changes almost every year, which is why, unlike other vaccines, you need an annual flu shot to protect yourself. While symptoms can vary from year to year, generally you can expect to have a sore throat and cough as well as a stuffy nose. Your body will likely feel achy and fatigued. You could also experience headaches and chills. While not everyone will experience this, it isn’t uncommon for you to have a fever of 100 or higher. Children who catch the flu often experience diarrhea, vomiting, and nausea.