Sunday, we'll have to "spring forward" by setting our clocks ahead one hour for daylight saving time. For many of us, resetting our clocks is a simple matter. But for those who struggle with insomnia, daylight saving time can add to the difficulty of getting enough sleep, says Charlene E. Gamaldo, assistant professor in the department of neurology at the Johns Hopkins School of Medicine and assistant director of the Johns Hopkins Sleep Disorders Center.

Many of us have trouble falling asleep every now and then. When does having difficulty sleeping become defined as insomnia?

Insomnia is an umbrella term used to describe a syndrome or complex that occurs when an individual has trouble with initiating sleep and/or maintaining sleep and with that has problems functioning in the daytime.

There are 30 types or reasons for insomnia that can range from a primary sleep problem, such as sleep apnea or restless leg syndrome, to secondary reasons, such as anxiety, depression, pain or other medical problems or medications.

What are the most common causes of insomnia?

When looking for causes of insomnia, we would probably look to secondary causes like medications or other medical conditions before considering primary causes of insomnia due to sleep disorders.

How might daylight saving time affect those with insomnia?

Our bodies need certain cues that help the brain know when it is time to be asleep or awake. For example, receptors in the eye receive light and send triggers to your brain that it is time for sleep or time to be awake.

If you are getting daylight exposure later in the day, your brain will receive the trigger that it is time to sleep later, and that may make it more difficult [for some] to fall asleep.

How is insomnia -- and the causes for it -- diagnosed?

You basically would need a thorough evaluation. The sleep expert or doctor would work with you to draw up a step-by-step evaluation of how you prepare to go to bed, what the sleep environment is like and all the things that make the setting more or less conducive to sleep.

What steps should we take to set the scene, so to speak, for good sleep?

You always want to prime your body to get the optimal amount of good sleep. Begin by giving the body good cues in the morning with sun exposure, physical activity. These things are engaging and send the brain the clues that you are supposed to be awake. Get up at a standard time (that stays the same within 30 minutes).

And what about at night?

The corollary is to set the stage in the evening for good sleep by limiting the things that say "stay awake." These include limiting bright-light exposure late at night to things like TV and computer screens, especially if you are particularly sensitive to light.

Engage in relaxing activities such as reading. Limit your caffeine intake. Smoking is bad for you anyway, but if you smoke close to bedtime, it will make it harder to fall asleep. And don't drink alcohol within three hours of bedtime because once it leaves your system it actually gives you a rebound alertness. And your bedtime should be at the same time within 30 minutes every night.

If you are having trouble sleeping, when should you consult a doctor?

If your sleep is affecting how you function during the day. If you feel that the quality of life has decreased or your mood is altered, it should be discussed.

How much sleep does an adult need?

The recommendation by the American Academy of Sleep, based on research into sleep deprivation and when individuals perform at their best cognitively, is 7 1/2 to eight hours. There can be [exceptions], but most folks who think, "I can get four hours and function just fine," are really robbing themselves of their best.

Do we need less sleep as we age?

It is a myth that we need less sleep as we age. Many people think that as they get older, they need less sleep or that the quality of their sleep should lessen. It should be emphasized that the quality of our sleep is not something we should be resigned to: People have options of how to really improve the quality of their sleep and lives.

Have you ever experienced insomnia or sleep loss?

Oh, my goodness, when my daughter was born, I thought, "I've been on call; I've been prepared for this. It will be no big deal." ... The loss of sleep when you have a child was a lot worse. I think I felt on call all the time. She is 4 now and is sleeping through the night, but the experience remains vivid.