Kidney infections, also known as pyelonephritis, can cause various warning signs. Common symptoms include fever, chills, back or abdominal pain, frequent and painful urination, blood in the urine, cloudy or foul-smelling urine, nausea, and vomiting. In more severe cases, individuals may experience fatigue, confusion, and worsening symptoms. If you suspect a kidney infection, it is essential to seek medical attention promptly for diagnosis and appropriate treatment.