Get too little sleep each night and you may be putting yourself at risk for myriad health issues like weight gain, high blood pressure and a decrease in immune response. But many people find that even if they can find the time to get eight hours of sleep per night, they still feel exhausted in the morning. This may lead you to ask yourself, "How much sleep do I need?"

There's no question that adequate sleep is essential to human health. Though sleep is still rather mysterious to science, and more research is needed to determine exactly how chronic sleep loss can affect our bodies and minds, when we don't sleep enough we can experience problems with memory, metabolism, mood regulation, concentration, stress hormones and increased susceptibility to disease.

When we've gotten a restful night of sleep, we awake feeling refreshed and ready to face the day. But just how much is enough? Though eight hours is most often quoted as the ideal amount of sleep, studies have shown that people who sleep between 6.5 and 7.5 hours per night live the longest. Surprisingly, there is just as much risk associated with sleeping too long — defined as more than 8 hours per night — as there is with sleeping too little.

How many hours are best?

Sleep experts reveal that there is no "magic number" when it comes to the ideal amount of sleep; it varies from person to person. According to the National Sleep Foundation, two different factors affect each person's individual need for sleep: basal sleep need and sleep debt. Basal sleep need is the amount of time our bodies need for optimal performance, which is 7-8 hours for most adults. But that number is affected on an individual basis by sleep debt, which is the accumulated sleep lost to factors like insomnia, illness and environmental awakenings.

Adults are encouraged to aim for 7-8 hours of sleep per night as a rough target; it may be helpful to experiment with awakening an hour or so earlier or later than this goal to find the amount that makes you feel the best. Babies, children and teenagers, however, have different sleep needs than adults. Newborns should get between 12-18 hours, infants 3-11 months need 14-15 hours, toddlers 1-3 years should get 12-14 hours, preschoolers 3-5 need 11-13 hours and school-age children up to 10 years old need 10-11 hours. Teens aged 10-17 require 8.5-9.25 hours of sleep per night.

Tips for better sleep

How do you know if you're getting enough sleep? Dr. Michael H. Bonnet, a professor of neurology at Wright State University School of Medicine, says on that you should be able to awaken feeling refreshed without the need for an alarm clock. If you need the alarm to wake up, try getting to bed earlier by 15 minutes each night until you are able to awaken on your own. Bonnet also notes that if you're relying on caffeine to stay awake, you're probably not getting enough sleep.

If you have trouble sleeping at night, the Mayo Clinic recommends trying a few of these tricks. Stick to a consistent sleep schedule, going to bed and waking up at around the same time every day, even on weekends. Avoid consuming caffeine, alcohol and large meals in the hours leading up to your bedtime. Make sure your bedroom is dark and quiet, and give yourself time to wind down by taking a bath, reading a book or listening to relaxing music. Limit daytime naps, be sure to get physical activity during the day and manage your stress levels so you aren't kept up at night by worries about your daily life. If these sleep tips and tricks don't work for you, see your doctor to rule out sleep disorders or underlying health problems.

Got other thoughts on how much sleep you need? Leave us a note in the comments below.

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