How common is flank pain in urinary tract infection?

Urinary tract infections can affect the bladder or travel higher into the urinary system. Pain in the side or back beneath the ribs is more concerning for upper-tract involvement than the burning or pressure often felt with bladder irritation. Fever, chills, nausea, cloudy or strong-smelling urine, urgency, and passing urine often may occur. Flank pain can have many causes, so it should be interpreted with the rest of your symptoms rather than used alone to identify an infection.

Arrange medical advice for flank pain with urinary symptoms, fever, or feeling unwell. A clinician may test urine and decide whether treatment is needed. Drink normally if fluids are suitable for you, rest, and use only recommended pain relief. If treatment is prescribed, take it as instructed and seek review if symptoms do not begin to settle or return after treatment.

Get urgent help for severe pain, fever with shaking chills, vomiting that prevents drinking, confusion, faintness, or difficulty passing urine. Seek same-day advice during pregnancy, with kidney disease, a weakened immune system, or in a child or older adult. These situations can need faster assessment and treatment.

Ask whether the infection may involve the kidneys, which urine tests are needed, when improvement should begin, and which warning signs require urgent review. Tell the clinician about allergies, pregnancy, recent antibiotics, and previous urinary infections.