Nausea, weakness and lack of energy may be caused by the following reasons: 1. There are also a series of chronic diseases can also lead to these symptoms; 4, if there is a lesion in the nervous system, then it is also very likely to cause these conditions, such as trauma to the brain and epilepsy will lead to insufficient blood supply to the brain, so it will also be easy to make patients feel fatigue and weakness; 5, high blood fat can also cause nausea and weakness, high blood fat will also make patients easily feel fatigue, so patients do not have spirit, which is This is caused by the blood being too viscous and flowing too slowly.