There are two main reasons for soreness in the muscles of the whole body without exercise, as follows: First, due to the presence of cold in the resting state, such as during sleep at night, when the blood circulation is relatively slow, if there is cold will lead to muscle tissue becomes very tense, will also intensify the decline in blood circulation, the resulting lactic acid, inflammation and other metabolic products will appear to increase the accumulation. After this reaches a certain level, the peripheral nerves are stimulated, so it is easy to appear the performance of general muscle pain. Second, due to viral infection, such as influenza virus infection, the virus and the metabolites produced by the virus will affect the peripheral nerves of the human body, which will also cause generalized muscle pain and weakness. Third, it is also seen in rheumatism, rheumatoid arthritis, dermatomyositis and other rheumatic immune diseases, all of which may lead to generalized muscle aches and pains, so if it does not improve after rest, drinking more water, keeping warm and applying heat, it is best to go to the rheumatology and immunology department of the hospital for detailed examination.