Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Pyelonephritis: Kidney Infection ?
    ### Response:
    Symptoms of pyelonephritis can vary depending on a persons age and may include the following:
                
- fever  - vomiting  - back, side, and groin pain  - chills  - nausea  - frequent, painful urination
                
Children younger than 2 years old may only have a high fever without symptoms related to the urinary tract.
    