Sudden, severe pain in the side, back, lower abdomen, or groin
Pain that comes in waves and changes in intensity
Pain that may move from the back toward the groin
Blood in the urine
Cloudy or foul-smelling urine
Frequent urge to urinate
Pain or burning when urinating
Nausea or vomiting
Small amounts of urine or trouble passing urine
Restlessness or inability to find a comfortable position
Fever or chills
Urgent medical evaluation if pain is severe, blood is present, or fever occurs