Merck Manual

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Reviewed/Revised Sep 2023
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What is a concussion?

A concussion is an injury to your brain that temporarily affects your thinking and awareness.

The skull bone protects your brain. Fluid inside your skull also cushions your brain. However, if your head gets hit hard enough, your brain can move inside the skull and bump up against your skull. This may injure your brain and temporarily change the way your brain works.

What causes a concussion?

Concussions are caused by something hitting your head very hard (head injury). This can happen when, for example, you:

  • Fall and hit your head

  • Are in a car or motorcycle crash

  • Get punched in the head or hit on your head with an object

What are the symptoms of a concussion?

If you have a concussion, you may:

  • Be unconscious for a while (usually for less than 15 minutes)

  • Feel dazed, confused, or light-headed

  • Answer questions slowly

  • Have a headache, double vision, or sensitivity to light

  • Be clumsy or have poor balance

  • Have trouble remembering what happened just before or after you got hurt

What is post-concussion syndrome?

Post-concussion syndrome is when you have symptoms after your concussion. You may have:

Usually these symptoms go away in a week or two. Less often, these symptoms last for months.

How can doctors tell if I have a concussion?

Your doctor can tell you've had a concussion based on the symptoms you had after having a head injury.

In order to tell whether you've had any brain injury, doctors sometimes:

You may not need a CT scan if your symptoms went away in a few minutes after your head injury.

How do doctors treat a concussion?

Your doctor will have you:

  • Rest

  • Take acetaminophen if you have a headache

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
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