Osmolality
A direct read on how concentrated your blood is, central to hydration, sodium, and water balance.
Consider this test if:
- Investigating unexplained confusion, seizures, or altered mental status
- Tracking hydration and sodium balance alongside signs of dehydration or overhydration
- Evaluating low sodium that may point to SIADH or excess water retention
- Assessing antidiuretic hormone function or suspected diabetes insipidus
- Following kidney function, blood sugar control, or high urea levels
- HSA/FSA eligible
- Typical results in 1-3 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting is required. Recent fluid intake, alcohol, and hydration status directly affect the result, so the timing of collection relative to drinking or symptoms matters. Hemolyzed samples are rejected.
Video consult with your Care Team
A 1:1 call to discuss your health.
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What this test is for
Serum osmolality measures the concentration of dissolved particles in your blood, mainly sodium, glucose, and urea, and reflects how well your body holds water and electrolytes in balance. High osmolality points to dehydration, hypernatremia, high blood sugar, kidney dysfunction, or ingestion of substances like ethanol, methanol, or ethylene glycol, which is why it is used in toxicology and coma evaluation. Low osmolality points to overhydration, low sodium, or SIADH, a condition where the body retains too much water. It is also a key marker for assessing antidiuretic hormone function and the cause of unexplained seizures or altered mental status. Paired with a calculated osmolality, the gap between measured and calculated values can flag unmeasured toxins in the blood.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in 1-3 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
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Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
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Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
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Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
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Without membership
$0
pay as you go
At-cost pricing on labs, scans, and more
Priority turnaround on your results
On-demand clinician consults when you need guidance
Personalized action plans across supplements, exercise, nutrition, and sleep
AI health coaching to help you act on your results
Year-round medical support, with in-chat clinician escalation
All your health records in one personal vault, with trends and biological age tracking
Early access to new diagnostics and product releases
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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