Sodium · high result
What does a high Sodium mean?
Short answer
High sodium (hypernatremia) almost always means water loss exceeding intake — not eating too much salt. Dehydration from illness, heavy sweating, diuretics, uncontrolled diabetes, or an impaired sense of thirst (older adults, certain brain conditions) are typical causes; diabetes insipidus is rare. Mild elevations correct with fluids; significant ones need medical evaluation.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When does this result need same-day care?
- Sodium above about 150 mmol/L, or any elevation with confusion — same-day care
What is the normal range for Sodium?
- age 18+: 135 – 145 mmol/L
Often reflects dehydration or excess salt intake.
Full reference table, citations and testing options: Sodium biomarker page.
What are the common causes of high Sodium?
- Dehydration: inadequate water intake, fever, heat, vomiting, diarrhea
- Osmotic diuresis from very high glucose
- Diuretics, lithium (impairs water retention)
- Impaired thirst in older adults or neurological disease
- Diabetes insipidus (rare)
What symptoms go with high Sodium?
- Thirst, dry mouth
- Confusion, lethargy, irritability when marked
What do clinicians usually check next?
- Repeat after rehydrating
- Glucose, kidney function
- Urine osmolality if persistent
Follow-up tests available at TestWell: Glucose ($14.99).
How do you recheck Sodium?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Basic Metabolic Panel | Test · 8 biomarkers | $20.99 | Yes | 1–3 business days |
Common questions
Does a salty diet raise blood sodium?
Not in a healthy person — the kidneys and thirst keep it tightly regulated. High sodium on a lab test is a water problem, not a salt problem.
Sources
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.