Brachial Basilar Insufficiency Syndrome, also known as BBIS, is a medical condition characterized by insufficient blood flow to the brachial basilar system. This condition may result in various symptoms, including dizziness, vertigo, loss of balance, and weakness. Despite its specific name, BBIS is sometimes referred to by different synonymous terms in the medical field. One synonym for this syndrome is Subclavian Steal Syndrome, which describes the phenomenon of blood being redirected away from the brachial basilar system due to the occlusion or stenosis of the subclavian artery. Another synonym is Vertebral Basilar Insufficiency, as this condition directly affects the flow of blood to the vertebral and basilar arteries. Ultimately, all these terms signify the same underlying condition - inadequate blood supply to the brachial basilar system.