Stress is the body's response to demands placed on it and can be caused by both good and bad experiences. When stressed, the body releases chemicals that provide extra energy, which is beneficial for dealing with physical danger but can be harmful if the stress has no physical outlet. Stress can affect both the body and mind, causing tiredness, sickness, and inability to think clearly. There are various ways to manage stress, including exercise, eating healthy, relaxation techniques, positive thinking, getting enough sleep, and seeking help when needed. Lack of sleep can exacerbate stress and cause issues like depression, anxiety, slower metabolism, and irritability.