What should you know about flank pain?

Pain in this area can come from the muscles, ribs, spine, nerves, digestive organs, or urinary system. Kidney stones can cause severe, wave-like pain that may move towards the groin. A kidney infection may cause flank pain with fever, chills, nausea, or painful and frequent urination. A urinary tract infection can bring burning urination, urgency, or lower abdominal discomfort, although flank pain suggests that assessment should not be delayed. Pain after movement or a strain may behave differently from pain with urinary symptoms.

Note when the pain began, whether it is constant or comes in waves, its side and severity, and any fever, vomiting, urine changes, bowel symptoms, rash, or injury. Arrange medical advice for persistent, unexplained, or worsening pain. A clinician may examine your abdomen and back, check urine, and decide whether further tests are needed. Drink normally unless a clinician has advised a fluid restriction, and avoid taking medicines that are unsafe for you.

Seek urgent care for flank pain with fever or shaking chills, repeated vomiting, blood in the urine, inability to pass urine, severe weakness, or pain that is rapidly worsening. Emergency help is needed for collapse, confusion, severe abdominal pain, or flank pain after a major injury. Pregnancy, one functioning kidney, or significant kidney disease lowers the threshold for prompt assessment.

Ask which causes fit your symptoms, whether urine testing or imaging is needed, how to control pain safely, and which changes should bring you back urgently.