Dull ache and flank pain

Flank pain is felt between the ribs and hip, often on one side of the back. A muscle source may worsen with movement, twisting, or pressing the area. Kidney-related pain can occur with burning urination, frequent urination, blood in the urine, nausea, or pain that travels toward the groin.

A kidney infection commonly presents with flank pain alongside fever or chills and feeling unwell. Kidney stones may cause waves of severe pain, although discomfort can vary. A urinary tract infection may begin with urinary symptoms before pain develops.

Note which side hurts, when it began, whether movement changes it, and any urinary or digestive symptoms. Drink normally unless a clinician has given you a fluid restriction. Arrange an assessment if the ache persists, recurs, or is joined by urinary changes; a urine test or other examination may be needed.

Seek urgent care for flank pain with fever, chills, repeated vomiting, blood in the urine, inability to urinate, severe waves of pain, fainting, or confusion. These features can signal infection, obstruction, or another problem needing prompt treatment.

Ask whether your symptoms suggest a kidney infection, kidney stone, urinary tract infection, or muscle problem, and whether urine testing or imaging is appropriate.