When experiencing kidney stones, the pain is most commonly felt in the flank area, which is the side of the lower back just below the ribs. This pain can be very sharp and severe. As the stone moves through the urinary tract, the pain may radiate from the flank to the lower abdomen and groin. Men may experience testicular pain, and women might feel pain in the labial area. The pain often comes in waves and can vary in intensity. Other symptoms may include burning pain during urination, frequent urination, and blood in the urine.