It happens to most kids at one time or another: You wake up in the morning facing a new day -- only to yawn and wish you could go back to sleep. Several things can cause you to feel tired, but there are things you can do to avoid it. The amount of sleep you get each night is vital. You may think eight hours sounds like enough, but it isn't. Experts say that kids ages 5 to 12 need about 10 to 11 hours of sleep every night. Changes to your sleep schedule can also make you tired, and so can stress. Are you super-worried about a math test? That can affect how well you ... (more)