This condition is a nightmare, commonly known in some places as ghost bed press, in which one is frightened during sleep and feels something pressing on oneself and feels unable to move, usually related to the patient’s overwork, mental stress, endocrine disorders and mental anxiety and depression. It may also be related to the patient’s incorrect sleeping posture, i.e. unconsciously putting the upper limbs on the chest, and the heart compression may also cause breathing difficulties and other discomfort in the human body. Once in a while a nightmare is a normal physiological phenomenon, and there is no need to be too nervous about it.