A concussion is a brain injury that may result in a bad headache, altered levels of alertness, or unconsciousness.
It temporarily interferes with the way your brain works, and it can affect memory, judgment, reflexes, speech, balance, coordination, and sleep patterns.
See also: Concussion - first aid
Causes, incidence, and risk factors
There are more than a million cases of concussion each year in the United States.
A concussion may result when the head hits an object or a moving object strikes the head. A concussion can result from a fall, sports activities, and car accidents. Significant movement of the brain (jarring) in any direction can cause unconsciousness. How long a person remains unconscious may indicate the severity of the concussion.
Concussions don't always involve a loss of consciousness. In fact, most people who have concussions never black out. Some people have had a concussion and never even realized it.
Symptoms can range from mild to severe. They can include:
- Altered level of consciousness (drowsy, hard to arouse, or similar changes)
- Confusion, feeling spacey, or not thinking straight
- Loss of consciousness
- Memory loss (amnesia) of events before the injury or immediately after the person regained consciousness
- Nausea and vomiting
- Seeing flashing lights
- Sense of having lost time
- Changes in alertness and consciousness
- Convulsions (seizures)
- Muscle weakness on one or both sides
- Persistent confusion
- Persistent unconsciousness (coma)
- Repeated vomiting
- Unequal pupils
- Unusual eye movements
- Walking problems
Head injuries that result in concussion often are associated with injury to the neck and spine. Take particular care when moving patients who have had a head injury.
Signs and tests
A neurological examination may show abnormalities. The doctor will check your pupil size.
Tests that may be performed include:
A health care provider will do a brain and nervous system (neurological) evaluation to determine the right treatment for an uncomplicated concussion.
If a blow to the head during athletics leads to a bad headache, a feeling of being confused (dazed), or unconsciousness, a trained person must determine when the person can return to playing sports.
If a child or young adult has lost consciousness, that person should not play sports for a period of 3 months. There is an increased rate of brain injury and occasionally death in persons who have had a previous concussion that resulted in unconsciousness.
You may use acetaminophen (Tylenol) for a headache. Do NOT use aspirin, ibuprofen (Motrin or Advil), naproxen, or other similar drugs.
Eat a light diet. Light activity around the home is okay. You do not need to stay in bed. However, avoid exercise, lifting weights, or other heavy activity.
Have an adult stay with you for the first 12 - 24 hours after you are home from an emergency room.
- Going to sleep is okay. For at least the first 12 hours, someone should wake you up every 2 or 3 hours. They can ask a simple question, such as your name, and then look for any changes in the way you look or act.
- Ask your doctor for how long you need to do this.
Do not drink alcohol until you have completely recovered. Alcohol may slow down your recovery, increase your risk for another injury, and make it even harder to make decisions.
A concussion with bleeding or brain damage must be treated in a hospital.
Full recovery is expected from an uncomplicated concussion. Dizziness, memory loss, problems thinking, irritability, headaches, sleep disturbances, and other symptoms may occur continue for weeks or even months afterwards.
- Bleeding in the brain (intracerebral hemorrhage)
- Brain injury that results in physical, emotional, or intellectual changes or deficits
If someone has received a blow to the head, the person should be watched closely for signs of possible brain damage.
Calling your health care provider
Call your health care provider if anyone has a head injury that causes unconsciousness, or a head injury without unconsciousness that produces worrisome symptoms.
If symptoms do not go away or are not improving after 2 or 3 weeks, talk to your doctor.
Call the doctor if you have:
- Changes in behavior or unusual behavior
- Changes in speech (slurred, difficult to understand, does not make sense)
- Difficulty waking up or becoming more sleepy
- Double vision or blurred vision
- Fluid and blood leaking from your nose or ears
- Headache that is getting worse, lasts a long time, or is not relieved by over-the-counter pain relievers
- Problems thinking straight
- Problems walking or talking
- Seizures (jerking your arms or legs without control)
- Vomiting more than three times
Call 911 or go the emergency room if emergency signs develop.
Attention to safety, including the use of appropriate athletic gear, such as bike helmets and seat belts, reduces the risk of head injury.
Ropper AH, Gorson KC. Clinical practice: concussion. N Engl J Med. 2007;356:166-172.
Kirsch TD, Lipinski CJ. Head injury. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. Columbus, OH: McGraw-Hill; 2006:chap 255.
Heegaard WC, Biros MH. Head. In: Marx JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 38.
Jacob L. Heller, MD, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington, Clinic. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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