Are you tired of constantly feeling tired? If that's the case, NHS GP and TV doctor Amir Khan has pinpointed the most frequent causes of the issue - and outlined what steps you can take to address it . The NHS recommends that adults should target an average of seven to nine hours of sleep, while children need between nine and 13 hours depending on their age. If you've been experiencing tiredness for several weeks without understanding why, if your exhaustion is affecting your everyday life, or