What causes blackouts?
Blackouts may arise from a variety of conditions or events that affect the brain. Often, blackouts will result from a traumatic event or an event that involves head injury.
Traumatic causes of blackouts
Blackouts may often be caused by trauma to the head or brain including:
- Complications of brain surgery
- Electroshock therapy
- Injections and innoculations
- Mild head injury
- Phlebotomy (drawing a blood sample)
- Traumatic emotional event
Substance-related causes of blackouts
Blackouts can also be caused by a variety of drugs and other substances including:
Medication side effects, 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
Disease and disorder causes of blackouts
Blackouts can be caused by different diseases and disorders including:
Brain or spinal cord injury or tumor
Dehydration (loss of fluids and electrolytes, which can be life threatening when severe and untreated)
Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)
Epilepsy (disorder characterized by recurrent seizures)
Infections of the brain
Parkinson’s disease (brain disorder that impairs movement and coordination)
Serious or life-threatening causes of blackouts
In some cases, blackouts may be a symptom of a serious or life-threatening condition that should be evaluated immediately in an emergency setting. These include:
Looking for a Doctor?
Arrhythmias (irregular heartbeats)
Cardiomyopathy (weakened or abnormal heart muscle and function)
Heart valve diseases and disorders
Myocardial infarction (heart attack)
Questions for diagnosing the cause of blackouts
To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your blackouts including:
Can you remember things that happened recently?
Do you remember what you did after your blackout?
Do you remember what you were doing before your blackout?
Have you ever had a seizure?
Have you had any recent injuries or surgeries?
What medications are you taking?
What other symptoms occurred with your blackout?
When did your blackout occur?
When was your last drink of alcohol?
What are the potential complications of blackouts?
The potential complications of blackouts depend on the underlying cause. Because blackouts can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:
- Brain damage
- Injury during a blackout episode
- Neurological problems, such as memory loss and confusion
- Permanent nerve damage, including paralysis
Healthgrades Operating Company, Inc. All rights reserved. May not be reproduced
or reprinted without permission from Healthgrades Operating Company, Inc. Use
of this information is governed by the Healthgrades User Agreement.
- Memory loss. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003257.htm.
- Amnesia. University of Iowa Hospitals and Clinics Health Topics. http://www.uihealthcare.com/topics/mentalemotionalhealth/ment3141.html.