Before losing consciousness, some of the early signs and symptoms presented by vasovagal syncope patients include lightheadedness, nausea, extremely high or extremely low body temperature (often followed by sweating), tinnitus, palpitations, confusion, a slight inability to speak, often followed by mild stuttering, nervousness and visual disturbances are other symptoms that can occur as well [8].

The symptoms often last for a few seconds before the loss of consciousness begins. The loss of consciousness often happens when the individual is sitting up or standing. As soon as the sufferer passes out, they fall down. At this point blood flow to the brain is restored instantaneously. A seizure may result if the individual doesn’t fall into a fully flat supine position and the head stays elevated above the trunk as blood will unable to quickly return to the brain. 

There are many medical conditions that may cause syncope. This is why making the correct diagnosis for loss of consciousness is one of the most difficult challenges facing health care providers. The core of the diagnosis of vasovagal syncope is dependent on a clear description by the patient for a particular pattern of triggers and time course. It is very important to differentiate vertigo, seizures, light-headedness, seizures, vertigo and hypoglycaemia as other causes.

For patients with recurring vasovagal syncope, the accuracy of diagnosis can often be improved with any one of the following diagnostic tests [9]:

• Tilt table test
• Echocardiogram
• Holter monitor or event monitor
• Implantation of an insertable loop recorder
• Electrophysiology study

Vasovagal syncope often occurs in response to a trigger and there is often a corresponding malfunction in the parts of the nervous system which regulate the heart rate and blood pressure [4]. As soon as there is a slow-down in heart rate, the resulting lack of blood to the brain brings about fainting and confusion.

Below are some of the main triggers for vasovagal episodes:

• Sensitivity as a result of pain
• Extreme menstural pains
• Pressure on the chest after heavy exercising
• Being present during medical procedures
• Sight of blood
• Biopsy procedures (pre and post)
• Increased stress levels
• Dehydration
• Ingestion of certain medications and addcitive substances
• Heavy emotional swings
• Nervous malfucntions
• In rare cases, low sugar level in blood

The incidence for this condition is 6.2 cases per 100 patient years in the United States [5]. Syncope also reoccurs in less than 3% of affected individuals and also, 10% of affected individuals have a cardiac etiology. Data from around the world also suggest a similar occurrence rate to what is obtainable in the United States.

Vasovagal syncope occurs as a result of cerebral hypoperfusion [6]. Brain parenchyma is dependent on sustained blood flow to be able to provide a constant supply of glucose which is its major metabolic substrate. It is not possible for the brain tissue to store energy in form of high-energy phosphates as is seen in other areas of the body. This is why cerebral perfusion of between 3 to 5 seconds is enough to bring about syncope.

Cerebral perfusion is maintained relatively constant by an intricate and complex feedback system which typically involves arterial pressure, intravascular volume status, metabolic regulation and cerebrovascular resistance with intrinsic autoregulation. When there is a significant defect in any of these or subclinical defects in several of these systems, syncope may arise.

Syncope refers to a self-limited loss of consciousness accompanied by the inability to maintain postural tone. Most of the time, it is followed by spontaneous recovery [1]. The condition doesn’t include seizures, coma, shock or other such states of altered consciousness.

There are many recognised etiologies for syncope but categorization is made into reflex (neutrally mediated), orthostatic and cardiac so as to ensure proper initial evaluation [2]. Cardiac vasovagal syncope has the highest number of mortality while non-cardiac syncope doesn’t have such high mortality. Syncope can result in significant morbidity due to accidents or falls that may occur following its onset [3].

Vasovagal syncope refers to one of the most common causes of fainting. It occurs when the body begins to overreact to certain triggers. The most common triggers are sight of blood and extreme emotional distress.

The vasovagal syncope trigger kicks off a sudden drop in heart rate and blood pressure. This brings about a reduction in blood flow to the brain which leads to a momentary loss of consciousness.

The condition is often harmless requiring no treatment. However, it is possible for patients to get injured during an episode of the condition. The doctor may recommend tests to rule out more serious cases of fainting such as an underlying heart condition.