Sleep

We think getting adequate sleep is extremely important for good mental and physical health and that fatigue is often a sign that someone is getting inadequate sleep. On the other hand, "While most fatigue has root causes that are not medical in nature, a persistent lack of energy can be a sign of a serious problem, such as a thyroid disorder, anemia, depression, chronic fatigue syndrome or cancer. It is very important to see your doctor if fatigue persists."