Flank pain and headache: what to know

Flank pain and headache may occur together during illness or dehydration, but their combination needs context and symptom checks. Fever, chills, vomiting, urinary symptoms or feeling faint raise concern for an infection or another condition requiring medical review.

Not drinking enough, sweating, vomiting or diarrhoea can contribute to headache and concentrated urine, while a muscle strain can cause flank pain separately. A kidney infection can present with flank pain and fever, nausea or urinary discomfort; kidney stones may produce severe, wave-like pain and nausea. Headache may also come from a viral illness, poor sleep, tension or medicine use. The two symptoms do not identify one diagnosis by themselves. Examination and urine testing can help when the pain is near the kidneys or urinary changes are present.

Rest, take fluids in small regular amounts if you can drink safely, and note your temperature, urine colour, urinary symptoms and pain pattern. Avoid strenuous activity until a movement-related strain is clearer. Use only pain relief that fits your medical history and follow the label. Arrange a clinical review if symptoms last, recur, or are joined by urinary discomfort.

Seek urgent care for a sudden severe headache, stiff neck, confusion, weakness, fainting, repeated vomiting, high fever, severe flank pain, blood in urine, or inability to pass urine. Do not wait at home if you are becoming drowsy or cannot keep fluids down.

Could dehydration, infection or a medicine explain both symptoms? Should my urine, kidney function or blood pressure be checked? What pain relief is appropriate for me?