So many of my clients (and friends) complain about poor sleep or lack of sleep. Why do so many of us not sleep long, well and deeply? What’s going on here?

According to research, the average person (whoever he or she is) sleeps 6 to 8 hours a night, almost 50 hours a week, and more than 2,600 hours a year. Do the math: we spend almost 21 years of our lives asleep. Sleep is really important! Without good, deep and regular sleep, the quality of our work, relationships, and other activities usually suffer dramatically.

Day-time stress is a frequent cause of disturbed sleep. If you experience physical or psychological threats or believe that your needs aren’t being met, you activate the stress response: Your blood pressure rises, your heart beats faster and your adrenal glands crank out stress hormones. Over time, this physical response to stress not only contributes to poor sleep, it can also lead to hypertension, heart disease, and immune deficiencies.

There are dozens of books, articles and research laboratories designed to help people sleep. Despite all of this, most of us have realized that – unfortunately – you can’t force yourself to sleep. It’s just not possible to make yourself go to sleep in the same way you can make yourself run, exercise, read, or do any other voluntary activity. Ironically, “trying” to sleep usually makes it less likely to sleep well, because the harder you try and less successful you are, the more frustrated you’ll feel. See the cycle? How can we not “try” so hard when we really want that good, deep sleep?

There are many ways to change your life to make good sleep more probable. While none of these are “sure things”, check out the suggestions below and consider the ones that speak to you.

Find ways to reduce the stress in your life during waking hours. This may include meditation, yoga, exercise, prayer, walks in nature, playing with your pets, gardening, reading something inspiring, dancing, etc. Whatever makes you feel better and reduces your stress during the day will help you sleep better at night.

Get into bed a half-hour before you turn out the lights, and read or listen to something soothing and calming. No television, BlackBerry or electronic diversion of any kind an hour or so before bed: they tend to be stimulating, not relaxing.

If you’re lying in bed and can’t sleep for more than 20 minutes…get up. Break the sleepless cycle. Get up and do something calming (like reading something pleasant and benign). Eventually, you’ll feel sleepy again…this is when you get back in bed.

Listen to sleep-inducing music or meditations on your iPod or CD player. When I wake up at 3 a.m., this is the fastest way for me to go back to sleep. It gives my mind something to focus on besides my obsessive, worried thoughts.

Over-the-counter medications that contain sleep-inducing antihistamines are fine for a night or two, but they typically don’t work over the long term.

Consult with a doctor who is a board-certified sleep specialist. Doctors with that certification have passed a rigorous exam and have a thorough knowledge of sleep medicine. Go to the American Board of Sleep Medicine’s sleep center site (www.sleepcenters.org).

Consider cognitive-behavioral psychotherapy. It can help you change the behaviors and thoughts that get in the way of a good night’s sleep. The cognitive part of the therapy shows you how to change anxiety-producing thoughts that interfere with your ability to sleep. The behavioral part focuses on changing behaviors that impair your ability to sleep, like spending too much time in bed or not exercising during the day.

Whatever you chose to do about your sleep problems, take action. The most wasteful thing is not doing anything. The cost of not sleeping well is too great. Those 21 years of sleep are a necessary part of your physical and mental health. Make sure that they’re 21 years well spent (happily and deeply asleep, in bed).