Swallowing syncope refers to the brief loss of consciousness triggered by swallowing. This temporary blackout can occur in various situations such as having blood drawn, straining during urination (known as micturition syncope) or bowel movements, and while coughing or swallowing. Emotional stress from fear or pain can also provoke this reaction. Just before fainting, individuals often experience paleness, nausea, sweating, and weakness. This phenomenon is caused by a reflex of the autonomic nervous system called the vasovagal reaction. During this process, the heart rate slows down (bradycardia) and the blood vessels in the legs dilate (widen), causing reduced blood output from the heart and a drop in blood pressure. As a result, blood circulation is redirected to the legs rather than the head, leading to a lack of oxygen in the brain and resulting in fainting. The vasovagal reaction is also known as a vasovagal response, while situational syncope is often termed vasovagal syncope or Gower’s sign, named after Sir William Richard Gower (1845-1915), a renowned English neurologist who has several medical terms named after him, including a sign, a solution, another syndrome, and a tract in the nervous system.
