Pyelonephritis patients usually present in the emergency department with sudden development of pain radiating to the flank in the presence of dysuria and fever. The differentiation of pyelonephritis from other causes of dysuria is based on severity of symptoms and the typical radiation of pain. A thorough history and examination is required to differentiate pyelonephritis from other causes of dysuria and flank pain.

Patients with pyelonephritis can present with the history of following important findings:^[1]

• Sudden symptom onset
• Fever
• Recent urinary tract infection
• Diabetes
• Immunosuppression
• Known structural defect of the urinary tract
• Renal stones
• History of pyelonephritis
• Tumor
• Cyst or abscess in the urinary tract

Patients with pyelonephritis can report the following symptoms:^[1][2][3][4]

• Fever– usually high grade
• Dysuria (painful voiding of urine)
• Abdominal pain (radiating to the back on the affected side)
• Rib or back pain
• Rigors (violent shivering while the temperature rises)

• Frequency
• Urgency
• Hematuria
• Constitutional symptoms (fatigue, decreased appetite)
• Nausea and vomiting
• Delirium
• Headache

Pyelonephritis in infants and children less than 2 years may present as:

• Fever
• Fussiness
• Decreased appetite
• Signs of urinary tract infection may be missing

In elderly, pyelonephritis can present as:

• Confusion
• Disoriented speech
• Hallucinations

Urinary symptoms of pyelonephritis can include:

• Frequency (frequent urination)
• Urgency (urgent need to urinate)
• Nocturia (need to urinate at night)
• Dysuria (painful urination)
• Low volume voids
• Hematuria (blood in the urine)
• Foul or strong urine odor
• Abnormal urine color (cloudy)

• Abdominal pain or pain radiating to the flank
• Nausea and vomiting

• Pressure in the lower pelvis or back
• Flank pain or back pain

In elderly, pyelonephritis may present as:

• Disorientation
• Delirium

• Tachycardia