Tests & procedures
Lithium blood tests
Why regular blood tests matter while taking lithium, and how to prepare for them.
Why it matters
Lithium works within a narrow range — too little may not help, and too much can be harmful — so regular blood tests check the level in your body and that your kidneys and thyroid are healthy.
How to prepare
Step by step
Before
Keep to your usual dose and your normal salt and fluid intake.
On the day
Blood test taken about 12 hours after your last dose.
After
Your team reviews the level plus kidney and thyroid results.
Staying safe between tests
Keep well hydrated, keep your salt intake steady, and check with your doctor before starting new medicines (including anti-inflammatories), as these can change your lithium level.
Where this information comes from
Demonstration content — not clinician-approved. Governance-approved patient information must replace it before any clinical use or sharing.
This sheet is general information, not personal medical advice. Always follow the instructions from your own doctor or pharmacist.