Merck Manual

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Gordon Mao

, MD, Indiana University School of Medicine

Reviewed/Revised Mar 2023

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 Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most 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. Athletes who have had concussions should return to play gradually, after specific steps in their rehabilitation.

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.

Drugs Mentioned In This Article

Generic Name Select Brand Names
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Aphen, Apra, Children's Acetaminophen, Children's Pain & Fever , Children's Pain Relief, Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
Anacin Adult Low Strength, Aspergum, Aspir-Low, Aspirtab , Aspir-Trin , Bayer Advanced Aspirin, Bayer Aspirin, Bayer Aspirin Extra Strength, Bayer Aspirin Plus, Bayer Aspirin Regimen, Bayer Children's Aspirin, Bayer Extra Strength, Bayer Extra Strength Plus, Bayer Genuine Aspirin, Bayer Low Dose Aspirin Regimen, Bayer Womens Aspirin , BeneHealth Aspirin, Bufferin, Bufferin Extra Strength, Bufferin Low Dose, DURLAZA, Easprin , Ecotrin, Ecotrin Low Strength, Genacote, Halfprin, MiniPrin, St. Joseph Adult Low Strength, St. Joseph Aspirin, VAZALORE, Zero Order Release Aspirin, ZORprin
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