What should you know about left and right flank pain?

The flank is the area between the lower ribs and the hip, beside the spine. Pain on one side may follow lifting, twisting or a blow and can worsen with movement. Kidney-related pain may feel deeper and can spread towards the groin. Pain on both sides can still have several explanations, including muscle strain or urinary problems.

Kidney Stones can cause intense, wave-like pain with nausea or blood in the urine. A Kidney Infection may cause flank pain with fever, chills, feeling unwell or painful urination. A Urinary Tract Infection often causes burning or frequent urination, but symptoms can vary.

Note whether the pain changes with movement, meals or urination, and record fever, vomiting, urine colour and how much you are passing. Gentle activity may help a muscular ache, while fluids should be taken according to your clinician’s advice, especially if kidney disease or fluid restriction applies. Arrange assessment for new, persistent or recurring pain; a urine test and examination may help separate urinary from musculoskeletal causes.

Get urgent help for flank pain with fever and shaking chills, repeated vomiting, inability to pass urine, severe worsening pain, fainting, confusion or visible blood in the urine. Seek prompt advice after an injury or if you are pregnant, have one functioning kidney or feel significantly unwell.

Ask whether the pattern suggests a muscle, kidney or urinary cause, whether urine or imaging tests are appropriate, and which changes should prompt emergency care. Mention recent injuries, urinary symptoms and medicines.