Scientists don't always understand why some people who endure a stressful and frightening event—such as a very turbulent airplane flight—go on to develop a phobia while others don't, Lagos says.
In general, phobias tend to run in families and they even may be hereditary, Lagos says. "Often, phobias of certain situations or objects may be wired into our brains, as they were useful to our survival long ago," Rego says. "People who reacted with fear in dangerous situations were the ones who survived and reproduced."
Although the trigger for a phobia may differ, the symptoms of all the various phobias are remarkably similar, Lagos says. Feelings of terror and impending doom, a rapid heartbeat and breathing, and sweaty palms are common. Just anticipating a phobic trigger can bring on symptoms, she says. "Someone who is afraid to fly could start having episodes of a pounding heart and sweaty palms at the mere thought of getting on a plane in two weeks," she says.
Are phobias worth treating? That depends. If you have a phobia that is easy to avoid (like snakes), you probably don't need treatment. Likewise, if you have a phobia of flying but you don't need to fly and are comfortable taking trains when you need to travel, you can probably get by. But if the phobia is making it hard for you to function in your life and/or causing you a lot of distress, treatment may be your best  option, Rego says. In particular, cognitive behavioral therapy is considered the treatment of choice for specific phobias, he says.
"It is often helpful, during treatment, to put yourself in the context where new learning can occur, such as by facing the feared object and then getting in closer and closer contact with it for as long as it takes to learn something new about it," Rego says.
Say you are terrified of dogs. In treatment, you may first spend some time in the same room with a dog. The dog may then be moved a little closer to you. "If your anxiety goes back up, then the process pauses and you examine your fears," Rego says. "In so doing, the anxiety usually starts to recede, at which point we move the dog a little closer, until eventually the dog is right at your feet. We wait until the anxiety starts to recede, and then try again, until the dog is right at your feet."
Besides cognitive behavioral therapy, biofeedback can also be helpful in treating phobias, Lagos says. In biofeedback, she explains, an individual learns how the body expresses anxiety responses like hyperventilation, muscle tension, cold hands or feet, and how the mind fuels these responses with danger and doom. With the guidance of a biofeedback therapist, an individual can learn to reduce anxiety and fear, Lagos says.
Leah Lagos, Psy.D., BCB, and Simon Rego ABPP, ACT reviewed this article.