Urinary tract infections can cause fever and vomiting. The early stage of urinary tract infection is mainly manifested as frequent, urgent and painful urination, i.e., pus and blood urine. When the symptoms are aggravated by poor treatment or ineffective treatment, the infection may be retrograde to the kidneys, leading to pyelonephritis, which may show pain in the lower back, generalized chills, fever, and even nausea and vomiting. In this case, it means that the infection symptoms are more serious, you need to go to the hospital urology department for help, to do urine bacterial culture plus drug sensitivity test, as well as the need for infusion support and other treatment.