Can docs explain what does tear gas do to the human body?

It is a lacrimator.: ω-chloroacetophenone (CN) & o-chlorobenzylidenemalononitrile(CS) are the 2 most common tear gas components. Tear gas is a lacrimator, it irritates mucous membranes of the eyes, causing pain & tears & irritates the respiratory tract, leading to coughing & choking. The effects are time-limited which makes it ideal for riot control.