Does kidney infection cause flank pain?

Kidney infection can cause aching or tenderness in one side of the back, beneath the ribs, or toward the waist. The discomfort may feel deeper than a muscle strain and can occur with fever, chills, nausea, tiredness, frequent urination, or burning when passing urine. A kidney infection often develops after bacteria travel upward from the bladder. Flank pain alone has other possible causes, including muscles, the spine, or a urinary stone, so its pattern and accompanying symptoms matter.

Arrange prompt medical assessment if flank pain occurs with fever, urinary symptoms, vomiting, or feeling generally unwell. A clinician may ask about the onset and location of pain, examine your abdomen and back, and request a urine test. Take prescribed treatment exactly as directed and drink fluids if you can keep them down, unless a clinician has given you a fluid restriction. Do not use leftover antibiotics.

Seek urgent care for severe or rapidly worsening pain, confusion, fainting, repeated vomiting, inability to keep fluids down, or very little urine. Fever with flank pain can need quick treatment, particularly during pregnancy or when you have diabetes, a weakened immune system, or known kidney problems. Emergency help is appropriate if you become difficult to wake or have trouble breathing.

Ask whether your symptoms fit a kidney infection, whether urine testing is needed, and which warning signs should bring you back. You can also ask how to take the prescribed medicine, when improvement should begin, and whether a stone or another cause needs checking if the pain continues.