Difference Between Seizure and Passing out

Seizure and passing out are two commonly misunderstood medical conditions that can cause confusion and concern for individuals who experience them. Both of these conditions involve loss of consciousness, but there are significant differences between the two. Understanding these differences is important for effective diagnosis and treatment.

What is Seizure?

The abnormal electrical impulses in the brain's cortex cause the strange behaviour known as a seizure.

  • Symptoms − Twitching and other uncontrollable action of the limbs and body, mental confusion, a loss of consciousness and awareness, and a fixed stare are only few of the symptoms that can accompany seizures. Sometimes, incontinence can occur after a seizure that lasts up to two minutes.

  • Diagnosis − Diagnosis can be aided by a physical examination and by documenting the symptoms during a seizure. An electroencephalogram (EEG) records and analyses brain electrical activity. One of the best non-invasive tests for epilepsy. The doctor often does what is called a "neurological exam," in which he or she examines several aspects of our nervous system. When an infection of the brain is suspected, a lumbar puncture may also be performed. Seizures may be caused by tumours or bleeding in the brain, both of which can be detected using a CT scan or MRI.

  • Causes − Seizures can happen for a variety of causes, including but not limited to the following: brain damage, brain tumours, brain infections, neurological disorders including epilepsy, substance addiction, alcohol withdrawal, and heredity.

  • Risk factors and treatment − Risk factors for seizures include substance misuse, brain injury, and a family history of the disorder. Perhaps treating the underlying cause. Topiramate, pregabalin, carbamezapine, and gabapentin are only some of the drugs that can be utilised. Depending on the age of the patient and the kind of seizure, different anti-seizure drugs may be effective.

What is Passing Out?

When a person passes out, they become temporarily unconscious. "syncope" is the medical name for fainting.

  • Symptoms − The individual becomes unconcious and begins to breathe more shallowly than usual; their pulse may slow down and their extremities may feel colder than usual. There is a loss of muscle tone and reflexes, but the person rapidly recovers.

  • Diagnosis − A syncope diagnosis can be made by a doctor by listening to the patient's history and taking note of any underlying health issues.

  • Causes − Reduced blood supply to the brain is the leading cause of passing out. As a result, this may occur under a wide variety of circumstances. One potential explanation is a decrease in cardiac output. Circulatory disorders and abnormal heart rhythms can reduce cardiac output. Syncope can also be brought on by a sudden drop in blood pressure, which can happen for a variety of causes. Low blood pressure, or syncope, can be brought on by dehydration. Syncope can be brought on by taking certain drugs or by neurological issues like a stroke or a transient ischemic attack. Those with hypoglycemia are at risk of passing out if their blood glucose levels drop too low since the brain requires a lot of sugar to operate. Syncope can be brought on by a variety of factors, including bleeding, discomfort, and even intense emotion.

  • Risk factors and treatment − Those who are unwell, especially those with heart or brain issues, are at increased risk of passing out. Low blood sugar and, in the case of women, heavy menstruation, are both risk factors for syncope. The treatment for syncope is condition specific. The patient with low blood sugar is given glucose; the patient with dehydration is given electrolytes and water; the patient with cardiac difficulties is given medicine or undergoes additional procedures.

Differences: Seizure and Passing Out

The following table highlights the major differences between Seizure and Passing Out −



Passing out


The aberrant brain electrical activity is what triggers the seizure.

Passing out or syncope occurs when a person reaches a condition of transient unconsciousness.


The signs of a seizure include twitching of limbs and body, lack of awareness of surroundings, occasionally a fixed look, and even incontinence.

The signs of passing out are a momentary loss of awareness, shallow breathing, sluggish pulse, and colder than normal arms and legs.


Seizure can be identified via a neurological exam, EEG test, CT or MRI scan, depending on the reason.

A doctor can diagnose passing out either by observing physical symptoms or by hearing patient history in order to rule out potential medical causes.


Seizures can be related to several diseases including: brain infection or severe damage, drug and alcohol withdrawal, brain tumour or haemorrhage.

Passing out also has various reasons such as a reduction in cardiac output, stroke, TIA, dehydration, hypoglycemia, discomfort, extreme emotion, and bleeding.

Risk factors

Risk factors for seizures include having a brain infection or trauma, withdrawal from alcohol or narcotics, brain tumour, or family history.

Danger factors for passing out include having some form of heart issue, sickness, significant bleeding, dehydration, blood sugar abnormalities, and being on certain drugs.


Anti-seizure medicines and possibly brain surgery are therapy options for seizures.

An intravenous (IV) infusion of glucose or electrolytes may be useful in treating fainting, albeit this depends on the underlying reason.


While both seizures and passing out involve loss of consciousness, they are distinct medical conditions that have different causes, symptoms, and treatments. Understanding the differences between the two can help individuals receive the right care and treatment for their specific conditions. If you experience any symptoms of either condition, it is important to seek medical attention immediately.

Updated on: 26-Apr-2023


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