Stomach and flank pain: what to know

Flank pain is felt at the side of the body between the ribs and hip, sometimes extending toward the back or lower abdomen. A pulled muscle may hurt more with movement, twisting or touch. Kidney stones can cause intense waves of pain that travel toward the groin, sometimes with nausea or blood in urine. A urinary tract infection or kidney infection may bring burning urine, frequent urination, fever, chills, or pain near the back. Digestive causes can produce cramping, bloating, constipation, vomiting, or changes in stool. The pattern and associated symptoms matter more than the word stomach alone.

Rest and note exactly where the pain is, when it started, whether it comes in waves, and what makes it better or worse. Record urinary changes, bowel movements, vomiting, fever, chills, and any blood. Drink normally unless a clinician has told you to restrict fluids; do not force large amounts when vomiting. Avoid taking someone else’s antibiotics. If the pain is mild and clearly follows a muscle strain, gentle movement and a suitable over-the-counter pain reliever may help, provided you can take it safely. Arrange a clinical review if the cause is unclear or the pain does not settle.

Seek urgent care for severe or rapidly worsening pain, fainting, confusion, a rigid abdomen, repeated vomiting, inability to pass urine, or blood in urine or stool. Prompt assessment is needed for flank pain with fever or chills, painful urination, pregnancy, or a single functioning kidney. Emergency help is appropriate when pain comes with breathing difficulty, chest pain, collapse, or marked weakness.

Does the location and pattern suggest a kidney, urinary, digestive or muscle cause? Do I need a urine test or imaging? Which changes in pain, urine or temperature should bring me back urgently?