Hello and thank you for asking HCM I have read your question and i understand your concerns. Before we start,if possible i need to know if you did an urine test,or urine culture to know what type of bacteria was in your urine,and to know the antibiotic to be used.So if you have them,please show me the results. The most common bacteria,responsible for our UTI is escherichia coli. This bacteria lives in our colon and every time,this bacteria moves to our urinary tract, usually from urethra it gives UTI. It can be treated easily with antibiotics. BUT if for some reason the antibiotics don t work,yes it might get even your kidneys and give pyelonephritis. I suppose that your doctor used the right antibiotic for you, so i would rule out the possibility of a kidney infection. Just to be sure,i will write you some of the symptoms that everyone has,if the infection goes at your kidneys. -Back pain -Fever -Nausea -Vomitus Most of the times,if the kidney is infected,you will have fever,so if for some reason you have fever and one of the other symptoms,you need to check up with your doctor. Also i will write below,the symptoms of UTI,so this way you will be able to see if there is an UTI in your body or not. -A strong, persistent urge to urinate. -A burning sensation when urinating -Blood in the urine (hematuria) -Pelvic discomfort. -A feeling of pressure in the lower abdomen. To keep your urinary tract clean and to help it to fight infection,you can use some of the best natural antiseptics like chamomile tea, Marshmallow Root Tea,peppermint-ginger-juniper berry tea. Also drinking a lot of fluids,usually 2-3 liter each day,helps our kidneys to work normally and lowers the possibility to have a UTI. If you have any other question,feel free to contact me any time. Wishing you good health. Dr.Endri Katro