I got pyelonephritis when I was 14. It was weird - I didn’t even know anything was wrong till I got up one morning, went to the bathroom (though I did notice my pee had a bad odor), then went back to bed to hang out for a bit, and suddenly my abdomen started to hurt. Within a few minutes it got to the point where I was literally writhing in pain. My mom came in to see what was wrong. Eventually she decided to call an ambulance, and before it arrived I threw up. The ambulance comes and the paramedics take me to the ambulance in a chair type thing and transported my mom and I to the hospital. When I was there I threw up again, my mom had to help me hobble over to the bathroom for a urine sample, and I got an IV. Once we waited a few hours, we got the results. I’ll never forget how the doctor described the urine - she likened it to a Christmas tree where nothing was supposed to light up, but everything lit up.
So yeah, not fun at all.