Lithium Level Test
A blood test that measures lithium to keep it in the safe and effective range.
Quick Summary
To monitor lithium treatment in bipolar disorder.
Lithium level 12 hours after the last dose.
Take the test about 12 hours after your last dose.
Overview
Lithium has a narrow safe range.
Kidney and thyroid tests are done too.
What It Measures
Lithium
Blood level.
How It's Performed
- 01
Preparation
Usually no special preparation unless your doctor advises.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm.
- 03
Afterwards
Press on the spot; a small bruise is common.
Reference Ranges
Note: Normal ranges vary by laboratory. Consult your report for the specific reference used.
| Parameter | Typical Range (Adult) | Units |
|---|---|---|
| Lithium (maintenance) | 0.4–1.0 | mmol/L |
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories; use the range on your report. Your doctor will explain what your result means and what happens next.
If values are Low:
Low levels may not work well.
If values are High:
High levels can be toxic.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Therapeutic Drug Monitoring(opens in a new tab) · MedlinePlus, US National Library of Medicine