Anxiety disorders are when people are suddenly overcome by intense fear or discomfort for no reason; or worry too much about events or activities; or have persistent fear of an object or situation, such as flying, heights, dark rooms, or animals for no reason; or spend too much time each day doing things over and over again.

Physical symptoms can include shaking, upset stomach, rapid heartbeat, sweating, fainting, trouble breathing, headaches, irritability, and sleep problems.