By Diana Fair Michigan State University Extension BIG RAPIDS - We all know that we feel better after a good night's sleep. We have more energy, are more alert, better able to think and perform cognitive activities and we just feel happier in general. In contrast, after a poor night's sleep we often feel fatigue, less alert, cranky and experience problems with our memory. According to the Division of Sleep Medicine at Harvard Medical School, "sleep plays a critical role in immune function, metabolism, memory, learning and other vital functions." Sleep research is producing interesting sleep information for all of us. Here are some major reasons why sleep is important to a person's health: Body systems have a chance to rejuvenate during sleep. This includes muscle repair and growth, as well as hormone production. Sleep is critical for infant and child brain development. This also includes teenagers, who, like infants, may need between 10 to 12 hours of sleep a night. The amount of time spent sleeping affects our ability to learn and to perform mental tasks. Getting adequate sleep increases a person's ability to maximize brain activity while lack of sleep causes individuals to forget and perform poorly on tests and other mental tasks. Sleep deprivation may increase the risk of serious injury or accidents, including car accidents. More than 100,000 car accidents occur every year from driver fatigue. For most individuals, research between lack of sleep and disease is critical. A critical loss of sleep over time increases a person's risk for developing many chronic diseases including diabetes, heart disease and obesity. With the development of chronic disease often comes a shortened life expectancy. Lack of sleep can lead to increased cortisol production. Cortisol causes increased inflammation in the body and the increased risk of developing a chronic disease. How much sleep do we need a night? Most researchers recommend seven to eight hours of sleep per night for adults. Michigan State University Extension recommends these tips to help people sleep: Try to go to bed at the same time every night. Develop soothing bedtime habits such as enjoying a warm bath or reading. Avoid drinking alcoholic and caffeinated drinks. Engage in physical activities every day. Pay attention to your sleep patterns. If you're not sleeping long enough or are experiencing sleep-related disorders, try developing healthier sleep habits. For more information on how to develop healthier lifestyle habits, connect with MSU Extension at your local county office or online. This article was published by Michigan State University Extension. For more information, visit msue.msu.edu.