The symptom of sleeping feeling suddenly stepping on air is caused by the weakened control of the higher neurons of the brain over the lower neurons during human sleep, which induces nerve impulses and leads to muscle contraction. The feeling of suddenly stepping on air while sleeping is usually a normal physiological phenomenon, usually occurring when you first fall asleep or when you are about to wake up, mainly due to the high-level neurons in the brain are in a sleep state, its control over the low-level neurons in the brain is weakened, and slight stimulation can cause the low-level neurons to produce nerve impulses, causing muscle contraction, resulting in the feeling of suddenly stepping on air. This muscle contraction in the sleep state patients are generally not aware of, in the dream state will be manifested as a roll over and fall or suddenly stepping in the air, this dream occurs, the patient is often suddenly awakened. Suddenly stepping on the air during sleep, patients do not need to be too concerned, do not need to be too nervous, in fact, most people have had this experience, before going to bed should be adjusted emotionally, to maintain a relaxed state can be.