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By Medicover Hospitals / 11 Feb 2021
Home | symptoms | blackouts
  • Blackouts are the lack of consciousness or the total or partial loss of memory. Possible causes of fainting include epilepsy and drinking a large amount of alcohol. If a person notices that someone is unconscious, they should place them in a sitting position or help them lie down so that they do not hurt themselves.
  • Article Context:

    1. What is blackout?
    2. Types
    3. Causes
    4. Diagnosis
    5. Treatment
    6. When to visit a Doctor?
    7. Prevention and Home Remedies
    8. FAQ's

    What is blackout?

  • Fainting spells are periods of loss of consciousness or memory. Generally, a blackout is described as a period of unconsciousness or lack of consciousness in which you cannot remember what happened or what you did. Fainting can occur because of brain damage, drug side effects, excessive alcohol use, or disorders that affect brain function, such as epilepsy. Blackouts can also be due to a recent traumatic event, in which case you may forget everything that happened just before or immediately after the event (anterograde amnesia). Unexplained power outages, or blackouts that appear to be due to injury or trauma, should be evaluated by a medical professional.
  • Types of blackouts:

    Alcohol blackouts:

  • Two different types of blackouts can occur from drinking alcohol: block and fragmentary.
  • When a person consumes a large amount of alcohol, a blockage blackout can occur. If this happens, they won't remember anything they did while drinking. Fragmentary blackouts affect only memory patches, so a person can reconstruct a memory by receiving prompts.
  • Alcohol blackouts:

  • There are two main types of syncope blackouts: neural and cardiac in origin.
  • A neurally mediated syncope is usually benign and does not require further treatment. It could occur when a person's blood pressure drops after experiencing pain or dehydration or getting up too quickly. This type of syncope tends to occur more often in children and young adults.
  • Cardiac syncope is more serious, as it could indicate an underlying heart problem. Tachycardia, bradycardia, or other types of hypotension can cause cardiac syncope. If a person does not receive treatment, they are at risk of complications or even sudden cardiac death.
  • Epilepsy:

  • The neuronal activity disruption in the brain can cause an epileptic episode. During these episodes, people can experience seizures. Your muscles can contract and lose consciousness.
  • However, just because a person has epilepsy does not necessarily mean that they pass out when they have a seizure. The disorder is a spectrum and covers many other symptoms.
  • Causes:

  • Blackouts can arise from a variety of conditions or events that affect the brain. Often several, fainting will result from a traumatic event or an event involving a head injury.
  • Traumatic causes of blackouts:

  • The following can cause ocular eye pain that originates from the surface of the eye:
    • Complications of brain surgery
    • Concussion
    • Electroshock therapy
    • Injections and inoculations
    • Mild head injury
    • Phlebotomy
    • Traumatic emotional event

    Causes of substance-related blackouts:

    • Alcohol intoxication
    • Side effects of medications, such as the side effects of cancer treatments or seizure medications, or agents used for anesthesia.
    • Poisons, such as cleaning chemicals or pesticides
    • Recreational drug use

    Causes of diseases and disorders of blackouts:

    • Anemia
    • Brain or spinal cord injury or tumor
    • Cardiac arrhythmia
    • Dehydration
    • Dementia
    • Depression
    • Encephalitis
    • Epilepsy
    • Brain infections
    • Nutrient deficiency
    • Parkinson's disease
    • Postural hypotension
    • Vasovagal syncope

    Causes of serious or life-threatening blackouts:

    • Arrhythmias
    • Cardiomyopathy
    • Epilepsy
    • Diseases and disorders of the heart valves
    • Myocardial infarction
    • Seizures
    • Serious infection
    • Stroke
    • Traumatic injury


  • If a person experiences fainting from syncope, a doctor may order an electrocardiogram (EKG) to see if there are any underlying problems with the heart.
  • If a doctor suspects that a person has epilepsy, they can order an MRI or CT scan. These imaging methods allow the doctor to analyze brain activity and rule out other neurological disorders.
  • If a person believes that they have psychogenic blackouts, a doctor may refer them to a neurologist who can diagnose psychogenic blackouts by eliminating other causes.
  • Treatment:

    • If a person shows symptoms of severe alcohol intoxication, a very high blood alcohol concentration can make it difficult for the person to remain conscious. In the most severe cases of alcohol intoxication, they can even slip into a coma. Because of this, it is very important to seek emergency help if your condition is deteriorating.
    • A doctor may prescribe fludrocortisone to reduce fainting in people experiencing neurally mediated syncope.
    • If someone feels like they are about to faint, they should sit or lie down so as not to hurt themselves if they fall unconscious.
    • People who experience psychogenic blackouts can benefit from cognitive-behavioral therapy (CBT). CBT helps people identify stress triggers and use coping techniques when they feel overwhelmed.

    When to visit a Doctor?

  • A person should speak to a doctor if they think they are experiencing symptoms of syncope, epileptic fainting, or fainting spells that result from medication. In cases of severe alcohol poisoning, a person may need emergency help. Most people will resume their everyday lives with medication. If a person's fainting spells related to an underlying medical condition, they should stop once the person receives treatment to control the condition.
  • Blackout prevention:

  • Besides abstaining from alcohol, moderation and pace are important to prevent blackouts. Avoid binge drinking, which defined as having five or more drinks in about two hours for men, or four or more drinks for women.
  • To avoid blackouts, you must:
    • Eat a strong meal or snacks before and during alcohol consumption.
    • Drink slowly: Sipping, rather than gulping, will help you keep track of how alcohol affects the body.
    • Hydrate body:Consider drinking a glass of water between alcoholic drinks to limit how much and how quickly you consume alcohol.

    Frequently Asked Questions:

  • Most power outages will end almost as soon as they start, but some can last much longer, days or even weeks.
  • A seizure occurs when there is an increase in this electrical activity. This causes several physical symptoms, such as muscle twitching, visual disturbances, and fainting. Seizures can affect the entire brain.
  • The possible complications of blackouts depend on the underlying cause. Because fainting can be caused by serious illness, failure to seek treatment can lead to serious complications and permanent damage.
  • Several studies have found that psychological conditions such as anxiety, depression, and panic attacks are linked with syncope, in particular vasovagal and unexplained syncope.
  • Citations:

  • JSTOR -
  • Taylor and Francis online -
  • Wiley's Online Library -