Medical Council of Canada

Medical expert

Polyuria and/or Polydipsia - 110-2


Although not common, polyuria and/or polydipsia may be the presenting symptom(s) of a potentially serious underlying condition. It may be confused with urinary frequency, a common complaint.

Causal Conditions

(list not exhaustive)
  1. Water diuresis
    1. Excessive intake
    2. Excessive loss - diabetes insipidus
  2. Osmotic diuresis
    1. Sugar - diabetes mellitus
    2. Urea - chronic renal disease
    3. Salts - organic anions

Key Objectives

Given a patient who presents with polyuria and/or polydipsia, the candidate will diagnose the cause, severity, and complications, and will initiate an appropriate management plan.

Enabling objectives

Given a patient with polyuria and/or polydipsia, the candidate will

  1. list and interpret critical clinical findings, including
    1. diagnose polyuria/polydipsia, causal factors, and severity, differentiating urinary frequency from polyuria;
    2. inquire about any personal or family history of diabetes;
    3. identify neurological features that may suggest intracranial pathology as a cause of central diabetes insipidus;
  2. list and interpret critical investigations, including
    1. tests which distinguish between water and osmotic diuresis;
    2. screening for diabetes;
    3. use of a voiding diary, when appropriate;
  3. construct an effective initial management plan, including
    1. management of the underlying cause;
    2. determination as to whether the patient requires specialized care.
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