Sleep is essential for virtually all living creatures. This is very important for humans because without sleep they cannot function properly. Sleep can affect humans in all kinds of ways when they engage in different activities. Like driving, working or doing everyday things. Sleep can affect our daily lives and various factors can cause sleep disorders, lack of sleep and health problems. As well as medical issues that can lead to sleep problems. Humans need sleep to survive, it can affect us physically, mentally and will affect us differently with little or no sleep as well as with different types of sleep. Sleep affects humans mentally and physically. This can affect them mentally with sleep and mental health problems. They are tired, more irritable and less focused. According to the article “Contemporary Sleep Medicine for Patients,” “Sleep is defined as a reversible state of decreased responsiveness to the environment” (Iochimescu, 3). There is also the problem of sleeping too much. This happens when a person sleeps for a long time and wakes up still tired. Not sleeping or sleeping too much can affect human health. It is important to know how well a person sleeps. There are many steps to sleep better. The individual must ensure that they are consistent with the changes. Some changes include sleeping and waking up at the same time each day, avoiding naps, and creating a bedtime routine (Kiplinger, 1997). Sleep is a very valuable thing for human beings and there is still tons of information that researchers haven't found yet. It will always be an important topic in a person's life. This is because all humans need sleep to survive. Many factors can affect your sleep, such as medical conditions, but there are also many ways your sleep can affect your health and lifestyle. It's important for people to know how sleep affects them, because only they can improve it and learn from it. Humans sleep to have a healthy immune system, a healthier mind, and a healthier life.