Your Serum and Urine Sodium Levels Are Normal
Your serum sodium of 143 mmol/L is completely normal (135-145 mmol/L), and your urine sodium of 34 mmol/L simply reflects your body's appropriate response to your dietary sodium intake. 1, 2
Understanding Your Results
Serum Sodium: 143 mmol/L (Normal)
- This falls well within the normal range of 135-145 mmol/L 1, 3
- There is no hyponatremia (low sodium) or hypernatremia (high sodium) present 1
- This level indicates proper sodium-water balance in your bloodstream 3
Urine Sodium: 34 mmol/L (Appropriate)
Your urine sodium is not "low" - it's actually appropriate for normal physiology. Here's why:
- In healthy individuals, urine sodium varies widely (typically 20-200 mmol/L) depending on dietary intake 2
- A urine sodium of 34 mmol/L suggests you're consuming a relatively moderate sodium diet 2
- This level indicates your kidneys are functioning normally and appropriately conserving or excreting sodium based on your intake 2, 4
Why You Don't Need Cirrhosis or Heart Failure to Have These Values
The misconception here is that low urine sodium only occurs in disease states - this is incorrect. 1, 2
Normal Physiological Variation
- Urine sodium <30 mmol/L typically indicates sodium retention, which occurs in volume depletion or when dietary sodium intake is low 2
- Your value of 34 mmol/L is just above this threshold, suggesting moderate dietary sodium intake with appropriate renal handling 2
- Healthy individuals on sodium-restricted diets (1,500-2,000 mg/day) commonly have urine sodium values in the 30-78 mmol/L range 2
When Urine Sodium Becomes Clinically Significant
Urine sodium interpretation depends entirely on clinical context:
In disease states (which you don't have):
- Cirrhosis with ascites: Urine sodium <10 mmol/L suggests severe sodium retention requiring paracentesis 2
- Heart failure: Urine sodium <50-70 mmol/L after diuretics indicates inadequate response 2
- Hypovolemia: Urine sodium <20 mmol/L suggests volume depletion 1, 2
In your case with normal serum sodium:
- Your urine sodium of 34 mmol/L simply reflects normal kidney function responding to your dietary intake 2, 4
- This is not pathological sodium retention 2
What Your Results Actually Mean
Your kidneys are working perfectly. 4
- Normal serum sodium (143 mmol/L) indicates proper total body sodium and water balance 3
- Urine sodium of 34 mmol/L shows your kidneys are appropriately matching sodium excretion to your dietary intake 2
- The combination of normal serum sodium with urine sodium >20 mmol/L actually suggests good renal function 4
Dietary Context
- Average North American sodium intake: 3,000-4,600 mg/day (130-200 mmol/day urinary excretion) 2
- Recommended intake: 1,500-2,300 mg/day (65-100 mmol/day) 2
- Your urine sodium of 34 mmol/L suggests you're likely consuming a moderate, possibly restricted sodium diet 2
Common Pitfalls to Avoid
Don't interpret isolated urine sodium values without clinical context. 2
- Urine sodium must be interpreted alongside serum sodium, volume status, and clinical presentation 1, 3, 5
- A "low" urine sodium is only pathological when accompanied by abnormal serum sodium or clinical signs of disease 1, 2
- In the absence of hyponatremia, hypernatremia, or volume abnormalities, urine sodium simply reflects dietary intake 2
Your results require no intervention - they represent normal physiology. 2, 4