A phobia is an intense, irrational fear of a specific object, situation, or activity that poses little or no actual danger. Unlike normal fears, phobias are persistent and often lead to avoidance behaviors that can interfere with daily life. People with phobias often go to great lengths to avoid the thing they fear, even if it’s not a realistic threat. When confronted with the source of their fear, they may experience extreme anxiety, panic attacks, or physical symptoms like sweating, rapid heartbeat, or nausea.