3. Weakness or Fatigue
These two symptoms are fairly general and so they could be a sign of a kidney infection but they could also be the symptoms of a whole list of other medical issues, including both mental and physical. These issues can also come about simply as a result of physical or mental stress, such as an intense workout session or studying for many hours at a time.
However, if the weakness or fatigue does not go away after a period of a day or two in which physical and mental stress has been lowered then it may be a sign of kidney infection or another medical issue.
Other signs which may indicate that the weakness or fatigue is not just a part of regular life include joint pain with no apparent swelling, tenderness of lymph nodes, headache, muscle pain, sore throat, less satisfying sleep, and lack of concentration. If the fatigue or weakness occurs for weeks or even months then there is usually an underlying medical issue.