polyuria
This flowchart provides a very practical, systematic approach to diagnosing polyuria (excessive urination). To make this easier to digest, I’ve broken down the logic into a structured summary. 🏥 Diagnostic Pathway for Polyuria 1. Confirm True Polyuria The first step is a 24-hour urine collection. * True Polyuria: > 3 L/day. * Pseudo-polyuria: If the volume is normal, the issue is likely frequency or urgency (often caused by UTIs, BPH, or anxiety) rather than volume. 2. Rule Out Common External Factors Before doing deep metabolic dives, check for the "big two": * Diabetes Mellitus: Check blood glucose first. High glucose leads to osmotic diuresis (sugar pulling water into the urine). * Substances: Review use of diuretics, lithium, caffeine, or alcohol. 3. Basic Metabolic Screening Order blood tests to look for electrolyte imbalances or organ dysfunction: * Hypercalcemia or Hypokalemia (high calcium or low potassium). * Chronic Kidney Disease (CKD):...