Diagnosis involves a combination of clinical assessment and laboratory investigations. Key steps include:
1. History and Physical Examination: A detailed history focusing on recent fluid losses, infections, or cardiac symptoms is critical. Physical exam findings such as tachycardia, hypotension, dry mucous membranes, and poor skin turgor can indicate hypovolemia.
2. Laboratory Tests: Blood tests showing elevated blood urea nitrogen (BUN) and serum creatinine levels, along with a BUN/creatinine ratio greater than 20:1, suggest a pre-renal cause. Urine analysis revealing low sodium concentration and high specific gravity can also support the diagnosis.
3. Imaging: Ultrasound may be used to rule out post-renal causes and assess kidney size and structure.
