Cashews, like other tree nuts, can lead to complications or allergic reactions. Cashews contain gastric and intestinal soluble oxalates, albeit less than some other tree nuts; people with a tendency to form kidney stones may need moderation and medical guidance. Allergies to tree nuts such as cashews can be of severe nature to some people. These allergic reactions can be lifethreatening or even fatal; prompt medical attention is necessary if tree nut allergy reaction is observed.