What questions should be asked when evaluating a patient with hyponatremia?

Key Questions for Evaluating Hyponatremia

When evaluating a patient with hyponatremia, a structured assessment focusing on volume status, symptom severity, onset timing, and underlying causes is essential for appropriate management. 1

Volume Status Assessment

Physical Examination Questions

• Do you have symptoms of dehydration (dry mouth, thirst, decreased urination)?
• Have you experienced dizziness when standing up?
• Have you noticed any swelling in your legs, abdomen, or face?
• Have you gained weight recently without trying?

Fluid Balance Questions

• How much fluid do you typically drink in a day?
• Have you been drinking more water than usual recently?
• Have you had excessive vomiting or diarrhea recently?
• Have you been using diuretics or laxatives?

Symptom Assessment

Neurological Symptoms

• Do you have a headache?
• Have you experienced confusion, disorientation, or memory problems?
• Have you had any seizures?
• Are you experiencing unusual fatigue or weakness?
• Have you noticed changes in your balance or gait?

Timing and Severity

• When did your symptoms begin?
• Have your symptoms worsened over time?
• Have you had similar episodes in the past?

Medication History

Current Medications

• What prescription medications are you taking?
• Are you taking any over-the-counter medications?
• Do you use any herbal supplements or alternative medicines?
• Specifically ask about:
  • Diuretics (loop diuretics, thiazides)
  • Antidepressants (SSRIs, TCAs)
  • Antiepileptic drugs (carbamazepine, lamotrigine)
  • Antipsychotics (chlorpromazine)
  • Pain medications (opiates)
  • Desmopressin 2

Medical History

Relevant Conditions

• Do you have heart failure?
• Do you have liver disease or cirrhosis?
• Do you have kidney disease?
• Have you been diagnosed with adrenal insufficiency?
• Do you have thyroid problems?
• Have you had recent surgery, particularly brain or pituitary surgery?
• Have you had any recent infections, particularly pneumonia or meningitis? 3

Lifestyle and Environmental Factors

Recent Changes

• Have you changed your diet recently?
• Have you been exercising excessively?
• Have you been in unusually hot weather?
• Have you experienced significant stress recently?

Laboratory Assessment Context

Previous Results

• Have you had low sodium levels before?
• What was done to treat your low sodium previously?
• Do you know your usual sodium level?

Risk Factor Assessment

Special Populations

• For women: Are you taking oral contraceptives or hormone replacement therapy?
• For elderly patients: Have you had any falls or fractures recently?
• For patients with cirrhosis: Have you noticed worsening ascites or mental status changes? 3

Pitfalls to Avoid

1. Don't miss hypovolemic hyponatremia - Always assess orthostatic vital signs and skin turgor
2. Don't overlook medication causes - Up to 30% of hyponatremia cases are medication-induced
3. Don't fail to classify by volume status - Treatment differs significantly based on whether the patient is hypovolemic, euvolemic, or hypervolemic 1
4. Don't ignore mild hyponatremia - Even mild cases (130-135 mEq/L) are associated with cognitive impairment, gait disturbances, and increased falls 4
5. Don't miss SIADH - Always consider this diagnosis in euvolemic hyponatremia
6. Don't overlook adrenal insufficiency - Can present with hyponatremia and should be considered in the differential diagnosis

Following this structured approach to questioning will help determine the etiology of hyponatremia and guide appropriate management decisions to improve patient outcomes.