Mental fatigue is a state of mind in which a person feels tiredness some people confuse it with weakness but both things are different. This feeling does not come quickly; it starts effective people rather slowing. This problem is also known as mental exhaustion, languor, listlessness, tiredness, lassitude and languidness. This problem can be lessening by taking proper rest which is not the case with weakness.
If we talk about physical fatigue it means is a temporary incapacity of muscles to main the regular movement and if a person keep exerting physical task without giving time to body to relax, this problem can get severe. Mental fatigue on the other hand is momentary reduction in cognitive performance that can cause because of too much cognitive activity. It can be observed by weariness, somnolence and direct attention fatigue.
Medical has not yet come up with all the symptoms of this problem so it can be caused by many things and can have many reasons. Fatigue itself is being considered a symptom not a sign because the patient tells about it as a prejudiced; it cannot be seen or observed by other people. People are still confused about what fatigue is and what the feeling of fatigue is.
Physical fatigue can happen with too much physical activity, in result muscles can reject to move properly, they started feeling heavier to move. This also depends on the physical fitness of the person; if a person is physically fit he will be able to exercise for more time without feeling any such problem but if a person have less power and is not fit physically he may start feeling pain in muscles very soon. It also matter that how much a person is used to these physical performances. People who do it on regular basis so not feel any pain for long time but one who do these activities rarely will start getting tire in minutes.
Mental exhaustion can be caused because of lack of proper sleep and overall health of a person. This problem can also cause lake in physical and mental performance of a person. A person will feel headache, cloudy mind and heavy eye all the time. He will take time in understanding things properly. It will decrease the level of awareness in a person, this problem can cause much severe issue when you have task to do which required too much attention and concentration and an active mind. A person can even have microsleep during his tasks that can endanger lives of many people.