Overview of Convulsions

Girl holding her head on a sunny day possibly suffering from heatstroke

 coffeekai / Getty Images

A convulsion describes an episode characterized by erratic, usually involuntary physical movements, which may be accompanied by changes in consciousness. A convulsion can be a manifestation of a number of different medical conditions, including seizures, severe infections, electrolyte imbalance, drug or alcohol overdose, and drug or alcohol withdrawal.

Convulsions are often unexpected and generally cause concern for everyone involved. If you experience or witness a convulsion, it can be difficult to decide what you should do. If you or someone you know has had a convulsion, you likely have many questions about what that means for your overall health and what you should expect.


Convulsions are generally quite noticeable. They generally involve the whole body, but some involve only one area of the body, such as an arm or a leg. Convulsions may be brief in duration, lasting for only seconds, or they may continue for a long period of time and may continue until the medication is given.

Some of the key features of convulsions:

  • Rhythmic shaking or jerking
  • Unusual physical movements
  • Cannot voluntarily stop the movements
  • Impairment of consciousness (decreased consciousness or complete loss of consciousness)

What to Do

If you witness a convulsion, the first thing you should try to do is to ensure that the person who is having or has had a convulsion is not left alone while medical care arrives. Someone should call for medical attention as soon as possible. If you are alone with someone who is having a convulsion, the best course of action is to call for emergency help while you remain with the person who is having a convulsive episode.

If you are present while someone is having a convulsion, there is no need for you to physically intervene. If possible, keep sharp objects away and protect from ledges or elevated spots that could allow falling.

Once medical help arrives, describe what you saw to healthcare professionals in as much detail as you can, particularly in regard to how the episode started. Be sure to report any falls or injuries that you are aware of. If you know that any substances were used, such as medications or drugs, be as honest and specific in reporting this as you can, because these details can speed up appropriate medical treatment, which can potentially prevent long-lasting health consequences.

If you think that you may have experienced a convulsion, you should call for medical attention as soon as it is possible for you to do so, and describe your experience in as much detail as possible.


There are many medical problems that can manifest as a convulsion.

Convulsions can be caused by health issues that directly involve the brain, or they may be caused by severe systemic (whole body) medical conditions that affect brain function.

The most common causes of convulsions include:

  • Convulsive seizure
  • Medication reaction
  • Severe infection, sepsis (infection that spreads through the blood)
  • Very high fever
  • Severe vomiting and/or diarrhea
  • Diabetic crisis (extremely high or low blood sugar levels)
  • Hydration abnormalities—severe dehydration or over-hydration
  • Severe malnutrition
  • Excessive blood loss due to trauma or internal bleeding
  • Organ failure, such as acute renal failure
  • Severe allergic reaction
  • Drug overdose
  • Drug withdrawal
  • Heatstroke

Many of these medical conditions can cause extreme changes in the body, which may result in a convulsive reaction. Some of these conditions can produce fluid imbalances and/or electrolyte abnormalities that may lead to a convulsion. Electrolytes, such as sodium, potassium, and calcium must be maintained within a very specific concentration in the body in order to support normal physical functions. Fluid and electrolyte imbalances can interfere with normal brain functions, causing changes in consciousness and physical convulsions.


Diagnostic testing for a convulsion includes a physical examination and a history from whoever may have witnessed the episode. Additional tests are usually needed to help determine the cause of a convulsion.

  • Urine test: A urine toxicology screening and possibly a blood toxicology screening are often checked.
  • Blood tests: Blood electrolyte and glucose (sugar) levels, and red blood cell count (RBC) and white blood cell (WBC) counts may also be needed to evaluate the cause of a convulsion.
  • Imaging and electrodiagnostic testing: In some instances, electroencephalogram (EEG), X-rays, or brain imaging tests may be necessary.

If you have experienced a convulsion, you probably will not need to have all of these diagnostic tests, and you will only need the tests that your doctor considers necessary after examining you and listening to your medical history. Once the results of these tests reveal what type of medical condition could have led to the convulsion, a long-term treatment plan may be necessary to manage your illness and to prevent another convulsion.

Medical Conditions That May Be Confused With a Convulsion

There are a number of conditions that may be confused with a convulsion because they manifest with similar characteristics, which may include sudden, jerky, or involuntary movements. The most common conditions that may be confused with convulsions are:

  • Seizure/epilepsy: Some seizures, specifically tonic-clonic seizures, manifest as convulsions, while other seizure types do not resemble convulsions. Similarly, some convulsions are seizures, while some are not.
  • Psychotic episode
  • Myoclonus
  • Tics/ Tourette's
  • Spasms
  • Deliberately disruptive behavior
  • Creutzfeldt-Jakob disease


Because the causes of a convulsion are so varied, the treatment for a convulsion is initially focused on stabilizing your medical condition, which means that your medical team may need to initiate treatment even before the cause of the convulsion is identified.

However, your team will also work quickly to identify the cause of your convulsion. This process involves checking for abnormal fluid and electrolyte levels, drugs, infections and neurological conditions such as head trauma or stroke.

Once the emergency is under control, your doctor will proceed with a thorough evaluation to determine whether you have a medical problem that could predispose you to have a convulsion, such as epilepsy or organ failure. Treatment will then be tailored to managing the specific cause of your convulsion for the long term.

A Word From Verywell

A convulsion requires urgent medical attention. If you experience a convulsion or if you witness a convulsion, seek professional medical help promptly, as some of the causes of a convulsion can cause permanent consequences if they are not treated promptly.

A convulsion may be an important sign of a medical condition that requires attention. A convulsion may be the sign of epilepsy, but that is not necessarily the case. If you or a loved one has experienced a convulsion, there is a strong chance that your doctors will be able to identify the cause of your convulsion and administer short term and long term medical treatment.

Sometimes, a convulsion is caused by a one-time event, such as heat stroke or severe dehydration. In these instances, once you are medically stabilized, you should not be excessively concerned about having further convulsions. In fact, many people who experience a convulsion do not ever experience another one again in their lives.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. National Library of Medicine. MedlinePlus. Seizures. Reviewed February 27, 2018.

  2. U.S. National Library of Medicine. MedlinePlus. Convulsions - first aid - series—Procedure, part 2. Reviewed February 27, 2018.

  3. KidsHealth from Nemours. Febrile Seizures. Reviewed October 2018.

  4. Chen HY, Albertson TE, Olson KR. Treatment of drug-induced seizures. Br J Clin Pharmacol. 2016;81(3):412-9. doi:10.1111/bcp.12720

  5. Nardone R, Brigo F, Trinka E. Acute Symptomatic Seizures Caused by Electrolyte Disturbances. J Clin Neurol. 2016;12(1):21-33. doi:10.3988/jcn.2016.12.1.21

  6. Galizia EC, Faulkner HJ. Seizures and epilepsy in the acute medical setting: presentation and management. Clin Med (Lond). 2018;18(5):409-413. doi:10.7861/clinmedicine.18-5-409

Additional Reading