ARIA stands for amyloid-related imaging abnormalities. ARIA-E refers to brain swelling and ARIA-H refers to small bleeds or microhemorages visible on MRI. ARIA is a potential side effect of monoclonal antibody drugs, like Leqembi and Kisunla. Most cases of ARIA are mild, but in rare cases ARIA can be life-threatening. People who carry two copies of the genetic variant ApoE4 are at greater risk of developing ARIA while receiving monoclonal antibody drugs.