What is In general for "fatigue" means the inability to exercise physical or mental functions in common daily activities. In most cases fatigue may be mild and led back to one or more bad lifestyle habits. In some cases, instead, it can be a symptom of an underlying problem that requires medical treatment. Fatigue may look like: Temporary fatigue, which can sometimes be due to stress, overwork, poor sleep, worry, boredom, lack of exercise and has identifiable causes and remedies;chronic fatigue, whose psycho-physical symptoms create a serious temporary disability, but the applicant; it is a condition that develops almost constant fatigue over time and decreases the physical and mental capacity energy; It also speaks well of: psychical and mental fatigue, which can have symptoms such as drowsiness, reduced ability to react, the low mood, a reduced ability to concentrate and memory. For example, anxiety and depression can cause fatigue and even a strong emotional stress situations; muscle fatigue, which occurs when the body are less certain elements that produce ATP (or adenosine triphosphate, a molecule important for the metabolism of living beings because it represents the main form of energy storage). The reduction of ATP leads to a lower availability of sugar in the blood and a consequent reduced muscular performance.