Can lack of enough lithium or too much lithium cause anxiety?

[Dirtypaws]

Dh is on lithium for bipolar. Currently he's refusing to have a blood test as he's got a bee in his bonnet about the surgery. It's an uphill struggle but care provider mentioned too much or too little can lead to anxiety and he's really anxious ATM.

Does anyone have any experience? I'm worried about talking about it as he will think I'm taking sides with the surgery. His last blood test was 6 months ago.

Thanks

I have lots of experience of having too much and too little lithium at various times but don't think I've noticed anxiety as a symptom either way. It should be checked every 3 months really. Can he go somewhere else, to the hospital, for the test?