t hear, weakness, fatigue, nausea
and headache. Less common
symptoms include syncope, dyspnea, chest pain,
and neck
and shoulder pain. When symptoms occur they can vary greatly in expression from one individual to another.[2]
Hypotension, anemia, improper sleeping position or poor blood flow in the neck caused by too high pillow are several common causes of the reduced blood supply to the brain during sleep at night.