Dear Dr. K: In the past year I’ve had five panic attacks. Now, I’m always worried I’m going to have another at any moment. Is there anything I can do to prevent them?

Dear Reader: Panic attacks can be very unsettling. All of a sudden, you are filled with extreme fear or terror. You might be short of breath, have heart palpitations, chest pain or sweating or feel a smothering sensation. You probably fear that you are losing control. You might even think you are about to die.

A panic attack usually lasts five to 30 minutes. But it can continue for several hours. Sometimes the attacks occur in stressful situations, but often they begin for no apparent reason. They can even wake you from deep sleep.

Panic attacks are surprisingly common: About 5 percent of women and 2 percent of men suffer from them at some point in their lives. In my experience, panic attacks are not always accurately diagnosed. Some of my patients tell me they’ve had panic attacks, but describe something different and even more common: being nervous a lot of the time. In contrast, panic attacks come like a bolt out of the blue and can end just as quickly. A mental health professional is best qualified to make a diagnosis.

Various imaging studies have found that the parts of the brain that control fear are different in people who suffer from panic attacks. At the same time, stressful situations (the external environment) often trigger the attacks.

Treatment often eliminates panic attacks or makes them less intense. Antidepressants known as selective serotonin reuptake inhibitors, commonly called SSRIs, are very effective for panic disorder. The SSRIs fluoxetine (marketed as Prozac), sertraline (Zoloft) and paroxetine (Paxil) are commonly prescribed.

Medication often works best when combined with cognitive or behavior therapy or both. Cognitive therapy teaches patients to recognize the unreasonableness of the fears that cause panic. Behavior therapy may include gradual exposure to fear-provoking situations or using breath control as a way to fight panic.

Finally, eliminating or reducing caffeine (which can promote panic attacks) is essential.