There are several common causes of muscle soreness after waking up: the first one is suffering from the stimulation of undesirable factors during the night sleep, such as cold, lack of warmth coverage when sleeping, the muscles all over the body under the stimulation of cold, resulting in vasoconstriction, relative hypoxia and ischemia, accumulation of metabolites, and irritated muscle soreness when getting up in the morning. The second, seen in excessive daily work or exercise, leads to chronic strain or acute injury to muscles throughout the body. During the night sleep, due to the drop in blood pressure, blood circulation becomes slower, there are symptoms of increased local inflammation, and you will get up in the morning with muscle aches and pains all over your body. Third, if the sleep bed is not comfortable, such as the mattress is too soft or too hard, after sleeping for a long time, will also be able to lead to muscle pain symptoms in the morning.