A concussion is a minor traumatic brain injury (TBI) that may occur when the head hits an object, or a moving object strikes the head.
It can affect how your brain works for a while. A concussion can lead to a bad headache, changes in alertness, or loss of consciousness.
Causes, incidence, and risk factors
A concussion can result from a fall, sports activities, and car accidents. A big movement of the brain (called jarring) in any direction can cause you to lose alertness (become unconscious). How long you stay unconscious may be a sign of the severity of the concussion.
However, concussions don't always involve a loss of consciousness. Most people who have a concussion never pass out, but they may describe seeing all white, black, or stars. You can have a concussion and not realize it.
Symptoms of a concussion can range from mild to severe. They can include:
- Acting confused, feeling spacey, or not thinking straight
- Being drowsy, hard to wake up, or similar changes
- Loss of consciousness
- Memory loss (amnesia) of events before the injury or right after
- Nausea and vomiting
- Seeing flashing lights
- Feeling like you have "lost time"
The following are emergency symptoms of a concussion. Seek immediate medical care if there are:
- Changes in alertness and consciousness
- Convulsions (seizures)
- Muscle weakness on one or both sides
- Persistent confusion
- Remaining unconsciousness (coma)
- Repeated vomiting
- Unequal pupils
- Unusual eye movements
- Walking problems
Head injuries that cause a concussion often occur with injury to the neck and spine. Take special care when moving people who have had a head injury.
While recovering from a concussion, you may:
- Be withdrawn, easily upset, or confused
- Have a hard time with tasks that require remembering or concentrating
- Have mild headaches
- Be less tolerant of noise
Signs and tests
The doctor will perform a physical exam and check your nervous system. There may be changes in your pupil size, thinking ability, coordination, and reflexes.
Tests that may be performed include:
A more serious brain injury that involves bleeding or brain damage must be treated in a hospital.
Healing or recovering from a concussion takes time. It may take days, weeks, or even months for a child's condition to improve. Parents and caregivers must learn how to treat the child's symptoms, how to monitor for problems, and when to allow the child to return to normal activities.
Healing or recovering from a concussion takes time.
- It may take days, weeks, or even months.
- You may be irritable, have trouble concentrating, be unable to remember things, have headaches, dizziness, and blurry vision.
- These problems will probably go away slowly. You may want to get help from family or friends before making important decisions.
Long-term problems are rare but may include:
- Brain swelling (which can be life threatening), if you have a second concussion while still recovering from the first one
- Long-term changes in the brain (if you have future brain injuries)
- Symptoms of the concussion stay for a long period of time (in a small group of patients)
Calling your health care provider
Call your health care provider if a head injury causes changes in alertness or produces any other 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 the following symptoms occur:
- 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 or blood leaking from the nose or ears
- Headache that is getting worse, lasts a long time, or does not get better with over-the-counter pain relievers
- Problems walking or talking
- Seizures (jerking your arms or legs without control)
- Vomiting more than three times
Although you can't entirely prevent injuries in children, parents can take some simple steps to keep their children from getting head injuries.
To prevent head injuries in adults:
- Always use safety equipment during activities that could cause a head injury. These include seat belts, bicycle or motorcycle helmets, and hard hats.
- Learn and follow bicycle safety recommendations.
- Do NOT drink and drive. Do NOT allow yourself to be driven by someone who you know or suspect has been drinking alcohol or is otherwise impaired.
Ropper AH, Gorson KC. Clinical practice: concussion. N Engl J Med. 2007;356:166-172.
Hunt T, Asplund C. Concussion assessment and management. Clin Sports Med. 2009;5-17.
Biros MH, Heegard WG. Head injury. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 38.
Last reviewed 1/30/2012 by Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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