MSD Manual

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Gordon Mao

, MD, Johns Hopkins School of Medicine

Last full review/revision Jun 2021| Content last modified Jun 2021
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A concussion is an alteration in mental function or level of awareness caused by a head injury. A concussion may involve a loss of consciousness, can occur without obvious damage to brain structures, and lasts less than 6 hours.

In concussion, no brain damage can be detected on imaging tests, such as computed tomography (CT) or magnetic resonance imaging (MRI). Yet brain cells are temporarily damaged or dysfunctional. The person has temporary symptoms of brain dysfunction.

Symptoms of a concussion include one or more of the following:

Consciousness may be lost for a brief time, rarely for more than 15 minutes. Some people may not realize they have had a concussion.

Postconcussion syndrome refers to certain symptoms that sometimes occur for up to a few weeks after a concussion. These symptoms include one or more of the following:

  • Headaches

  • Difficulty sleeping

  • Fatigue

  • Problems with short-term memory

  • Difficulty concentrating

  • Sensitivity to light or noise

  • Personality changes, such as irritability or mood swings

Postconcussion syndrome symptoms are common during the week after concussion and commonly resolve during the second week. However, sometimes, symptoms persist for months or, rarely, years. People who have had a concussion also seem to be more susceptible to another one, particularly if the new injury occurs before symptoms from the previous concussion have completely gone away.

To diagnose a concussion, doctors need to make sure brain structures are not damaged. The use of CT, MRI, or both may be needed. If there is no structural brain damage, only the symptoms need be treated.

For concussion, acetaminophen is given for pain. Aspirin or another nonsteroidal anti-inflammatory drug (NSAID Nonsteroidal Anti-Inflammatory Drugs In some cases, treating the underlying disorder eliminates or minimizes the pain. For example, setting a broken bone in a cast or giving antibiotics for an infected joint helps reduce pain.... read more ) should not be taken because they interfere with blood clotting and may contribute to bleeding from damaged blood vessels. Rest of both the body and the brain is the best treatment for a concussion.

Treatment for postconcussion syndrome is based on the severity of the symptoms. Rest and close observation are important. If symptoms worsen, people who have had a concussion should be taken to the doctor or hospital for evaluation.

People who experience emotional difficulties may need psychotherapy.

People should not return to contact sports after a concussion until all ill effects have resolved and medical evaluation has been completed.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

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Test your knowledge
Fractures of the Jaw and Midface
Fractures to one or more facial structures can result from a single injury. Jaw fractures may occur to the mandible, or lower jaw, or to the maxilla, bone of the upper jaw. Other structures susceptible to fracture include the eye sockets, nose, and cheek bones. Which of the following facial structures is most likely to fracture if a person falls from a great height or hits the windshield of a car face-first during a motor vehicle accident?
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