Patient presents with acute pyelonephritis, unspecified.  Symptoms include fever, chills, flank pain, costovertebral angle tenderness, nausea, and vomiting.  Urinalysis demonstrates pyuria, bacteriuria, and possible hematuria.  Differential diagnosis includes cystitis, ureterolithiasis, and appendicitis.  Patient's clinical presentation and laboratory findings support a diagnosis of acute pyelonephritis without specific organism identification at this time.  Blood cultures drawn and pending.  Treatment plan includes intravenous fluids, broad-spectrum antibiotics such as ceftriaxone, and pain management with analgesics.  Patient will be monitored for response to therapy and potential complications such as sepsis or renal abscess.  Diagnosis codes considered include N10, and ICD-10-CM code N10.9 for unspecified pyelonephritis.  Medical billing will reflect evaluation and management codes for the complexity of the visit, laboratory tests, and administered medications.  Follow-up urine culture and sensitivity will guide subsequent antibiotic therapy.  Patient education provided regarding hydration, medication compliance, and recognizing signs of worsening infection.  Return precautions discussed.  Further investigation into underlying predisposing factors, such as urinary tract obstruction or vesicoureteral reflux, will be considered if indicated by clinical course.