Biomarkers · Electrolytes & Minerals

Serum Sodium

Both low and high values go with higher risk of death. In NHANES 1999–2018 with linked mortality to 2019, each standard deviation above average goes with 9% lower risk of death. Risk rises at both ends: not comparable

Serum Sodium and risk of death

Published curve higher than the NHANES fitNHANES fit higher

Risk of death from our NHANES fit, relative to its reference value. The dotted vertical line marks the NHANES median.

Risk of death per SD (NHANES)0.91×95% CI 0.89–0.93 · 48,364 adults, 7,025 deaths

Value of the measurement+0.009gain in concordance within age bands; rank 37 of 56 · all tests

Serum Sodium by age and sex

Each bar runs from the 5th to the 95th percentile, the darker part from the 25th to the 75th, and the tick is the median. Not a reference range or a target.

The percentiles as a table

Each row is one sex and age band: the values below which 5%, 25%, 50%, 75% and 95% of people fall (mmol/L), from the survey named in the row. Not a reference range or a target.
Sex	Age	5th	25th	Median	75th	95th	n	Cycle / source
All	20-39	136	138	140	142	144	1,431	NHANES 2017-2018
All	40-59	136	138	140	142	145	1,548	NHANES 2017-2018
All	60+	136	139	141	142	145	1,891	NHANES 2017-2018
All	all	136	138	140	142	145	4,870	NHANES 2017-2018
Men	20-39	137	139	140	142	144	684	NHANES 2017-2018
Men	40-59	136	138	140	142	144	723	NHANES 2017-2018
Men	60+	136	138	140	142	145	958	NHANES 2017-2018
Men	all	136	139	140	142	145	2,365	NHANES 2017-2018
Women	20-39	136	138	140	142	144	747	NHANES 2017-2018
Women	40-59	136	138	140	142	145	825	NHANES 2017-2018
Women	60+	136	139	141	142	145	933	NHANES 2017-2018
Women	all	136	138	140	142	145	2,505	NHANES 2017-2018

What studies found when this marker was changed

They describe what happened in those study groups, not a recommendation. See all catalogued interventions.

Measured changes in Serum Sodium, study by study

2 effects with a numeric size, each from one study arm: the dot is the reported change, the line its 95% interval where one was given. Study results in the groups studied, not predictions for a person.

Each row is one study: what was changed, the effect it reported on this marker, and the source.
Type	Intervention	Reported effect	Evidence	Source
clinical	Fluid restriction (<1,000 mL/d) in syndrome of inappropriate antidiuresis (SIAD)	Fluid restriction (alone or with furosemide/NaCl) raised serum Na by 5 mmol/L from baseline 125 by day 4 (P<0.001)	RCT	Krisanapan P, et al. Efficacy of Furosemide, Oral Sodium Chloride, and Fluid…
pharmacologic	Vasopressin V2 receptor antagonists (Tolvaptan) in hypervolemic / euvolemic hyponatremia	Raised serum sodium more than placebo during the first 4 days and after 30 days (P<0.001); hyponatremia recurred after stopping	RCT	Schrier RW, et al. Tolvaptan, a selective oral vasopressin V2-receptor…

Things that worsen it

Each row is one study: what was changed, the effect it reported on this marker, and the source.
Type	Condition or exposure	Reported effect	Evidence	Source
clinical	Severe unreplaced water loss and hypertonic dehydration	Water dehydration from reduced intake is the most common cause of hypernatraemia in hospital (effect size not reported)	review	Brennan M, et al. Approach to the Management of Hypernatraemia in Older…
pharmacologic	Thiazide diuretic induced hyponatremia	Thiazide exposure: HR 4.95 (95% CI 4.12-5.96) for hyponatremia (sodium ≤135 mmol/L); moderate and severe risk 8 times higher	prospective cohort	Rodenburg EM, et al. Thiazide-associated hyponatremia: a population-based…

Sources

NHANES curve: our Cox model adjusted for age and sex, NHANES 1999–2018 with linked mortality to 2019.

Map Serum Sodium against another biomarker.

Map Serum Sodium against another marker