Getting a good night's sleep may be more important than you realize. A new study by the National Sleep Foundation has found that up to 47 million adults may be risking injuries or physical or emotional problems because they get too little sleep. The 2002 Sleep in America survey found a strong link between how people sleep and their moods, behavior, and ability to function on the job and elsewhere.

The NSF survey found that people who get enough sleep are more likely to say they feel alert, happy, energetic, and satisfied with life. Those who get too little are more likely to have feelings of anger, stress, pessimism, and fatigue. Even occasional insomnia can contribute to problems that range from road rage to obesity.

Sleeping well can be particularly difficult at this time of year, because your body may still be adjusting to the recent switch to Daylight Savings Time. And the rate of insomnia rose nationwide after the Sept. 11 terrorist attacks. The NSF has found that in 2002 fewer people are getting the recommended eight hours sleep than in 2001.

What can you do if you have trouble falling or staying asleep or waking up too early? Here are some tips:

• Have a bedtime routine. You might take a warm bath, listen to soft music, or turn the lights out at a certain time. Many people find that reading a book or magazine before bedtime helps them fall asleep more easily than watching television, which can contribute to insomnia if the volume is too loud or the programs are overstimulating. Be careful about online activities, too. Some people find it very hard to sign off once they've logged onto the Internet, and stay up hours later than they'd planned.
  
  
• Limit your consumption of caffeine (found in coffee, tea, cola drinks, and some over-the-counter painkillers) after five P.M. The effects of the caffeine in a cup of coffee typically last three to four hours, but they keep some people awake longer. It's also a good idea to avoid drinking alcohol before bedtime because-although it might seem to help you fall asleep quicker-it can wake you up during the night.
  
  
• Drink a cup of warm milk (or have a non-sugary snack made from milk products, such as cheese). Milk has an amino acid that may make you feel relaxed and get to sleep more easily. And a regular routine of heating the milk or cutting up cheese cubes may become a pleasant bedtime ritual.
  
  
• Avoid exercising in the three hours before bedtime. Getting regular exercise can help you sleep better, partly by making sure that you're tired enough to go to bed. But exercising (or doing strenuous housework) before bedtime can keep you awake. Be especially careful of doing very vigorous or aerobic activities in the late evening.
  
  
• If you keep having problems, ask your doctor if you could benefit from filling out a brief form known as a Global Sleep Assessment Questionnaire (GSAQ). In the past many sleep problems went untreated because the screening procedures were too time-consuming for most doctors to administer during a short office visit. The relatively new GSAQ has only eleven questions and can help you and your doctor decide whether you might benefit from making small adjustments in your routines or need a referral to a sleep disorders clinic for a more extensive evaluation of your concerns.