DefinitionLithium is a medication used to treat Bipolar disorder (manic depression). This article focuses on lithium overdose, or toxicity.Acute toxicity occurs when you intentionally or accidentally swallow too much of a lithium prescription.Chronic toxicity occurs when you slowly take a little too much of a lithium prescription every day for a while. This is actually quite easy to do, as dehydration, other medications, and other conditions can easily interfere with lithium in your body and cause it to build up.Acute on chronic toxicity occurs when you take lithium every day for bipolar disorder, but one day you take an extra amount (as little as a couple of pills or as much as a whole bottle).This is for information only and not for use in the treatment or management of an actual poison