We report the case of an 84-year-old woman with spinal subarachnoid hemorrhage who presented with disturbance of consciousness and nuchal stiffness, bloody cerebrospinal fluid and severe hypoglycorrhachia. Initially, it was difficult to determine whether this was a case of spinal subarachnoid hemorrhage, purulent meningitis, or hemorrhagic encephalitis, because of the nuchal stiffness, disturbance of consciousness and severe hypoglycorrhachia. It is known that intracranial subarachnoid hemorrhage is accompanied by mild hypoglycorrhachia, but descriptions of glucose levels in cerebrospinal fluid in cases of spinal subarachnoid hemorrhage are rare. This case suggests that both spinal subarachnoid hemorrhage and intracranial subarachnoid hemorrhage are associated with hypoglycorrhachia. Furthermore, spinal subarachnoid hemorrhage is frequently accompanied by disturbance of consciousness. Therefore, sudden back pain or lumbago might not be interpreted as indicators of spinal subarachnoid hemorrhage, because patients, particularly elderly patients, may lose consciousness. We emphasize that the possibility of spinal subarachnoid hemorrhage should be considered in patients with disturbance of consciousness or hypoglycorrhachia even if they do not complain of sudden back pain.