A sodium level of 155
| Where it fallscommonly reported adult reference ranges | Severe hypernatraemia |
|---|---|
| Sodium | 155mmol/L |
| Usual reference range | 135 – 145mmol/L |
| Severe hyponatraemia | under 120mmol/L |
| Moderate hyponatraemia | 120 – 129mmol/L |
| Mild hyponatraemia | 130 – 134mmol/L |
| Normal | 135 – 145mmol/L |
| Hypernatraemia | 146 – 154mmol/L |
| Severe hypernatraemiathis reading | 155 and abovemmol/L |
Notes
- A sodium of 155 mmol/L is outside the range a web page should be the end of. Repeat the measurement, and contact a doctor rather than reading further. If it comes with chest pain, breathlessness, confusion, weakness or a change in vision, treat it as an emergency.
- Reference ranges differ between laboratories. The bands above follow commonly reported adult reference ranges. Your own report prints the range its analyser was calibrated against, and that printed range is the one to compare against — a difference of a few units between labs is normal and does not mean either is wrong.
- Sodium measures concentration, not quantity. A low result almost always means too much water relative to sodium, not too little salt, and eating more salt is rarely the answer. The common causes are heart, liver or kidney disease, certain medicines — thiazide diuretics, SSRIs, carbamazepine — and the syndrome of inappropriate ADH.
- Speed matters more than the number. A sodium of 128 reached over weeks is often well tolerated, while the same value reached in a day can cause seizures. That is also why correction is done slowly: raising sodium too fast risks osmotic demyelination, a permanent injury, so a hospital will typically limit the rise to 8 mmol/L in 24 hours.
What sodium of 155 mmol/L means
A reading of 155 mmol/L falls in Severe hypernatraemia by commonly reported adult reference ranges.
The usual reference range is 135 – 145 mmol/L.
Reading it next to the rest of the picture
A single figure is a snapshot. What somebody experienced does with it is set by what sits around it — the other figures on the same report, the history behind them, and what the previous result was. Two people can hand over the same number and leave with different advice, and neither has been given the wrong answer.
That is also why the bands on this page are drawn from a named source rather than a rounded rule of thumb. A threshold is a decision point somebody argued for in print, not a law of nature, and knowing which document a line comes from is what lets you tell a meaningful result from a borderline one.
Nearby sizes
Read more
- CBC Normal Ranges — What Each Line on the Result MeansA value marked high or low on a CBC is common and is often not significant on its own. The pattern across lines is what a clinician reads.
- eGFR Normal Range: Above 90, and the Stages Below IteGFR is an estimate built from creatinine, age and sex — and the estimate is better than the raw creatinine it comes from, for a reason worth understanding.
- TSH Normal Range: 0.4–4.0 mIU/L, and the Number Moves BackwardsTSH runs opposite to the gland it measures. High TSH means the thyroid is underactive, and that inversion catches almost everyone reading their own result.
- Cholesterol Numbers: What Total, LDL, HDL and Triglycerides MeanA lipid panel reports four numbers and the one printed largest — total cholesterol — is the least useful of them.