Episodic stress is like lots of acute stress — in other words, lots of life changes — all at once and over a period of time. People who suffer from episodic stress always seem to be in the throes of some tragedy. They tend to be overwrought, sometimes intense, often irritable, angry, or anxious.

If you've ever been through a week, a month, even a year when you seemed to suffer personal disaster after personal disaster, you know what it's like to be in the throes of episodic stress. First, your furnace breaks down, then you bounce a check, then you get a speeding ticket, then your entire extended family decides to stay with you for four weeks, then your sister-in-law smashes into your garage with her car, and then you get the flu.

For some people, episodic stress becomes so drawn out a process that they become used to it; to others, the stress state is obvious. “Oh, that poor woman. She has terrible luck!” “Did you hear what happened to Jerry this time?”

Episodic stress, like acute stress, can also come in more positive forms. First, a whirlwind courtship, a huge wedding, a honeymoon in Bali, buying a new home, and moving in with your new spouse for the first time, all in the same year, is an incredibly stressful sequence of events. Fun, sure. Romantic, yes. Even thrilling. But still an excellent example of episodic stress in its sunnier, though no less stressful, manifestation.

Sometimes, episodic stress comes in a more subtle form — such as “worry.” Worry is like inventing stress, or change, before it happens, even when it has little chance of happening. Excessive worry could be linked to an anxiety disorder, but even when worry is less chronic than that, it saps the body's energy, usually for no good reason.

Worry doesn't solve problems. Worry is usually just the contemplation of horrible things that are extremely unlikely to happen. Worry puts your body under stress by creating or imagining changes in the equilibrium of life — changes that haven't even happened!

Are you a worrywart? How many of the following describe you?

• You find yourself worrying about things that are extremely unlikely, such as suffering from a freak accident or developing an illness you have no reason to believe you would develop. (Think Woody Allen and his imaginary brain tumor.)

• You often lose sleep worrying about what would happen to you if you lost a loved one, or what would happen to your loved ones if he or she lost you.

• You have trouble falling asleep because you can't slow down your frantic worrying process as you lie still in bed at night.

Like many other behaviors we think we can't control, worry is largely a matter of habit. So, how do you stop worrying? By retraining your brain! The next time you catch yourself worrying, get moving. It's hard to worry when your energy is directed toward following that exercise video or breathing in the fresh air as you run through the park.

• When the phone rings or the mail arrives, you immediately imagine what kind of bad news you are about to receive.

• You feel compelled to control the behaviors of others because you worry that they can't take care of themselves.

• You are overly cautious about engaging in any behavior that could possible result in harm or hurt to you or to those around you, even if the risk is small (such as driving a car, flying in an airplane, or visiting a big city).

If even just one of the worrywart characteristics describes you, you probably worry more than you have to. If most or all of these statements apply to you, worry is probably having a distinctly negative effect on you. Worry and the anxiety it can produce can cause specific physical, cognitive, and emotional symptoms, from heart palpitations, dry mouth, hyperventilation, muscle pain, and fatigue to fear, panic, anger, and depression. Worry is stressful.