Stabbing flank pain: what to know

Flank pain is felt between the ribs and hip, often toward one side of the back. A pulled muscle may hurt with movement, twisting or touch. Kidney stones can cause severe waves of pain that travel toward the groin, while a kidney infection can present with flank pain alongside fever, chills, nausea or urinary symptoms. A urinary tract infection may cause burning or frequent urination, although flank pain needs medical attention if it suggests the infection has moved upward.

Pain on one side does not identify its cause by itself. Note whether it began suddenly, moves, follows exercise, and comes with fever, vomiting, blood in urine, bowel changes, rash or difficulty passing urine.

Rest from movements that clearly trigger the pain, drink normally unless a clinician has restricted your fluids, and use only pain relief that is safe for you and taken according to its label. Arrange a clinical assessment if the pain persists, recurs or comes with urinary symptoms. A clinician may examine your abdomen and back and test urine.

Seek urgent assessment for severe or rapidly worsening pain, fever with flank pain, repeated vomiting, blood in the urine, faintness, confusion, inability to pass urine, or pain during pregnancy. Call emergency services for collapse, severe weakness or breathing difficulty.

Ask whether the pattern fits a muscle problem, kidney stones, kidney infection or another cause; which tests are needed; what pain relief is suitable with your medicines; and which changes should prompt immediate review.