Insomnia is the repeated inability to fall or stay asleep. It can cause tiredness, irritability, lack of energy and difficulty concentrating. Most people experience some level of insomnia but seek help if it lasts for over a month. Having a regular sleep habit can help solve insomnia. It's important to sleep when you are tired. The body needs to rest when tired, and regular, healthy sleeping habits are part of good health.
Attribution: Straight Talk Foundation