Dr. Susan Biali, author of Live a Life You Love: 7 Steps to a Healthier, Happier, More Passionate You, believes that getting enough sleep is absolutely essential to your emotional and physical well-being. Read on for her top 5 tips for better sleep.

Q: Why is sleep so important?

A: Sleep is so essential to our body - in terms of importance to our general wellness and survival, it's up there right behind oxygen, water, and food. When you get enough sleep regularly: you naturally enjoy a better mood and are less likely to suffer from or develop depression; you're less likely to experience hypertension or heart attacks and strokes; your body has the time to repair our tissues (and even can repair some of the skin damage done by UV light); your immune system functions better and can help you fight off minor illnesses such as colds and flu and even major illnesses like diabetes.

When you don't get enough sleep, your body experiences this as a major stressor and can produce increased levels of stress hormones. Chronic lack of sleep is associated with an increased risk of diabetes, heart disease, obesity and infections. When you haven't slept well it's also harder for you to concentrate and perform well throughout the day, and you're more likely to feel moody or irritable.

Q: Why do so many people suffer with sleep problems?

A: The majority of people today don't get enough sleep because of lifestyle issues. They may be working too much, or simply going to bed and getting up too early in order to accommodate their daily schedule. These days, the average person gets less than seven hours of sleep a night. In the early 20th century, the average person slept for nine hours.

When people get stressed and busy, it's very common for them to begin to cut into their hours of sleep in order to "find" more time in their day. What they don't realize is that in doing so, they make themselves far less productive (because of moodiness, poor concentration, and poor decision-making from lack of sleep), and it actually has more of a negative effect than a positive one.

In my speaking and coaching work I frequently hear from people who continually resolve to go to bed earlier - because they feel so exhausted and know it would make a huge difference - but get stuck again and again in the rut of late night email and Internet use, or late night television watching. Also, people who are stressed often find it hard to calm down their minds enough to fall asleep quickly and enjoy a deep restful sleep.

Q: What's the ideal amount of sleep?

A: Most people need 7-8 hours of sleep a night to feel well rested. However, that can change if you've missed many hours of sleep over time and have accumulated a large "sleep debt" (your body actually physically tracks this with a chemical, adenosine). I missed many nights of sleep in medical school and residency, so that may explain why my body seems to need 8-9 hours to feel great. Or, that might just be what my body needs. Either way, it's important to pay attention to what your body tells you and to respect that.

Q: What are your top tips for better sleep?

A: Commit to making a good night's sleep as essential to your health and life as making sure that you eat food throughout the day. Here are five tips:

1. Observe how many hours you seem to need to feel well-rested, and then plan your day's schedule around that. If you have to get up at 7 am for work, and need a good eight hours sleep to feel rested, plan to be in bed with the lights off at 11 pm. Enlist someone's help if necessary - my husband helps me stick to my sleep plan by dragging me away from the computer if I'm not practicing what I preach!

2. Avoid exposure to bright screens - such as a computer screen, or television screen, at least an hour before you go to bed. Bright screens can trigger your brain into thinking it's still daytime, causing it to secrete less melatonin. The result: you may have a harder time falling asleep and your sleep won't be as deep. Close to bedtime, turn down the lights and deliberately create a dim, cozy environment.

3. Avoid alcohol, caffeine and nicotine in the late afternoon and evening. A cup of coffee can take up to 8 hours to "wear off". And though alcohol can seem to make you fall asleep faster, it actually affects your REM sleep and significantly decreases the quality of your sleep and its restorative properties.

4. Create a sleeping space that promotes good sleep. Never take work into bed with you, put your TV anywhere but in the bedroom, avoid stressful clutter (I never allow myself to have a desk in the bedroom), and create a dimly lit, soothing space.

5. If you've made efforts to promote a better night's sleep but still find that you have great difficulties falling asleep, or staying asleep, or never wake up feel rested, see your doctor as there may be a medical cause for your challenges, such as a medical illness or sleep disorder.