A concussion may occur when the head hits an object, or a moving object strikes the head. A concussion is a minor or less severe type of brain injury, which may also be also called a traumatic brain injury.
A concussion can affect how the brain works for awhile. It may lead to a bad headache, changes in alertness, or loss of consciousness.
A concussion can result from a fall, sports activities, or car accidents. A big movement of the brain (called jarring) in any direction can cause a person to lose alertness (become unconscious). How long the person stays unconscious may be a sign of how bad the concussion is.
Concussions do not always lead to loss of consciousness. Most people never pass out. They may describe seeing all white, all black, or stars. A person can also have a concussion and not realize it.
Symptoms of a milder concussion can include:
- Acting somewhat confused, feeling unable to concentrate, or not thinking clearly
- Being drowsy, hard to wake up, or similar changes
- Loss of consciousness for a fairly short period of time
- 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 more severe head injury or concussion. Seek medical care right away if there are:
- Changes in alertness and consciousness
- Confusion that does not go away
- Muscle weakness on one or both sides
- Pupils of the eyes that are not equal in size
- Unusual eye movements
- Repeated vomiting
- Walking or balance problems
- Unconsciousness for a longer period of time or that continues (coma)
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.
Exams and Tests
The doctor will perform a physical exam. The person's nervous system will be checked. There may be changes in the person's pupil size, thinking ability, coordination, and reflexes.
Tests that may be done:
For a mild head injury, no treatment may be needed. But be aware that the symptoms of a head injury can show up later.
Your health care providers will explain what to expect, how to manage any headaches, how to treat your other symptoms, when to return to sports, school, work, and other activities, and signs or symptoms to worry about.
- Children will need to be watched and make activity changes.
- Adults also need close observation and activity changes.
Both adults and children must follow the health care provider’s instructions about when it will be possible to return to sports.
You will likely need to stay in the hospital if:
- Emergency or more severe symptoms of head injury are present
- Skull fracture
- There is any bleeding under your skull or in the brain
Healing or recovering from a concussion takes time. It may take days to weeks, or even months. During that time you may:
- Be withdrawn, easily upset, or confused
- Have a hard time with tasks that require memory or concentration
- Have mild headaches
- Be less tolerant of noise
- Be very tired
- Feel dizzy
- Have blurry vision at times
These problems will probably recover slowly. You may want to get help from family or friends for making important decisions.
In a small number of people, symptoms of the concussion do not go away. The risk of these long-term changes in the brain is higher after more than one concussion.
Seizures may occur after more severe head injuries. You or your child may need to take anti-seizure medicines for a period of time.
More severe traumatic brain injuries may result in many brain and nervous system problems.
When to Contact a Medical Professional
Call the health care provider if:
- A head injury causes changes in alertness
- A person has other worrisome symptoms
- If symptoms do not go away or are not improving after 2 or 3 weeks
Call the doctor right away if the following symptoms occur:
- Increased sleepiness or difficulty waking up
- Stiff neck
- Changes in behavior or unusual behavior
- Changes in speech (slurred, difficult to understand, does not make sense)
- Confusion or problems thinking straight
- 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 of the arms or legs without control)
- Vomiting more than three times
If symptoms do not go away or are not improving a lot after 2 or 3 weeks, talk to your doctor.
Although no child is injury-proof, parents can take some simple steps to help keep their children from getting head injuries.
Not all head injuries can be prevented. Increase safety for you and your child by following these steps:
- 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 may have been drinking alcohol or is otherwise impaired.
Heegaard WG, Biros MH, Head injury. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, Pa: Elsevier Mosby; 2013:chap 41.
Landry GL. Head and neck injuries. In: Kliegman RM, Stanton BF, St. Geme JW III, et al., eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 680.
Review Date: 1/15/2014
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.