Stabbing pain in the left flank: what to know

The left flank lies between the lower ribs and hip and can hurt after lifting, twisting or coughing when muscles are strained. Kidney stones may produce severe, cramping or wave-like pain that moves toward the groin. A kidney infection can present with flank pain, fever, chills, nausea or urinary changes. A urinary tract infection can cause burning and frequent urination, and flank pain alongside those symptoms needs prompt attention.

The side alone cannot identify the cause. Record whether the pain is constant or comes in waves, whether movement or touch changes it, and whether you have bowel changes, a rash, blood in urine or trouble passing urine.

Avoid strenuous activity while the pain is sharp, keep normal fluid intake unless you have been told to restrict it, and use only suitable label-directed pain relief. Arrange an assessment if pain continues, returns or is paired with urinary symptoms. A clinician may check your abdomen, back and urine.

Get urgent help for severe or escalating pain, fever, repeated vomiting, blood in urine, faintness, confusion, inability to pass urine or pain during pregnancy. Emergency services are appropriate for collapse, severe weakness or breathing difficulty.

Ask which causes fit the timing and location, whether urine or imaging tests are needed, which pain relief is safe with your health conditions, and what changes require emergency review.