Claustrophobia is an anxiety disorder characterized by an irrational fear of confined spaces. It can develop from a traumatic experience involving being trapped as a child or later in life. Symptoms when exposed to tight spaces include sweating, accelerated heartbeat, nausea, fainting, lightheadedness, shaking, and hyperventilation. Common situations that trigger claustrophobia include being in rooms, cars, buildings, or on airplanes. While there is no cure, treatments like behavior therapy, exposure therapy, and drugs can help manage the condition.