Over 40% of Americans don't get the recommended hours of sleep per night. That's scary, considering these are the same individuals driving on the roads, taking care of us in hospitals, building bridges, etc. Studies have shown that lack of sleep is as dangerous as driving under the influence. What difference could extra hour of sleep make in your life? Possibly a lot!! Studies show that the gap between getting just enough sleep and getting too little sleep may affect your health, your mood, your weight, and even your sex life.

If you are pregnant, you need even more sleep than you were getting previously. It is recommended that a pregnant woman get at least 8 hours of sleep per night. This may mean you have to be in bed for 10 hours due to the waking up to pee, constant rolling over and being uncomfortable, and leg cramps that wake you up. 

Most people need a good seven or eight hours of sleep a night. If you are not getting the recommended amount of zzzz's, here are nine reasons that you should shut down your computer, turn off the lights, and go to bed an hour early tonight.

1. Better health. Getting a good night's sleep won't grant you immunity from disease, but studies have found a link between insufficient sleep and some serious health problems, such as heart disease, heart attacks, diabetes, and obesity.

In most cases, the health risks from sleep loss only become serious after years. 

2. Better sex life. According to studies, up to 26% of people say that their sex lives tend to suffer because they're just too tired. There's evidence that in men, impaired sleep can be associated with lower testosterone levels.

3. Less pain. If you have chronic pain, getting enough sleep may actually make you hurt less. Many studies have shown a link between sleep loss and lower pain threshold. Unfortunately, being in pain can make it hard to sleep. Researchers have found that getting good sleep can supplement medication for pain. 

4. Lower risk of injury. Sleeping enough might actually keep you safer. Sleep deprivation has been linked with many notorious disasters, like the destruction of the space shuttle Challenger and the grounding of the Exxon Valdez. The Institute of Medicine estimates that one out of five auto accidents in the U.S. results from drowsy driving -- that's about 1 million crashes a year.

5. Better mood. Getting enough sleep can help put you in a better mood. When you're exhausted, you're more likely to be cranky, more likely to snap or burst into tears. 

6. Better weight control. Getting enough sleep could help you maintain your weight, and conversely, loss of sleep goes along with an increased risk of weight gain. Two reasons: Part of the problem is behavioral. If you're overtired, you may be less likely to have the energy to go the gym or cook a healthy dinner after work. The other part is physiological. The hormone leptin plays a key role in making you feel full, and when you don't get enough sleep, leptin levels drop. The result is people who are tired are hungrier, and they seem to crave high-fat and high-calorie foods.

7. Clearer thinking. Sleep loss affects how you think, it impairs your cognition, your attention, and your decision-making. Studies have found that people who are sleep-deprived are substantially worse at solving logic or math problems than when they're well-rested. They're also more likely to make odd mistakes, like leaving their keys in the fridge by accident.

8. Better memory. Feeling forgetful? Sleep loss could be to blame. Studies have shown that while we sleep, our brain processes and consolidates our memories from the day. If you don't get enough sleep, it seems like those memories might not get stored correctly and can be lost.

9. Stronger immunity. Could getting enough sleep prevent the common cold? One preliminary study put the idea to the test. Researchers tracked over 150 people and monitored their sleep habits for two weeks. Then they exposed them to a cold virus. People who got seven hours of sleep a night or less were almost three times as likely to get sick as the people who got at least eight hours of sleep a night.