What is a concussion?

A concussion, or mild traumatic brain injury, is a brain injury that occurs when force is transmitted to the brain causing it to move quickly within the skull.

This sudden movement causes a disruption in how parts of the brain communicate and results in symptoms. Medical providers refer to a concussion as a “mild” brain injury because concussions are not life-threatening. Even so, the effects of a concussion can be serious and cause significant temporary disability.

Learn more from the Centers for Disease Control and Prevention’s video.

What are the symptoms of a concussion?

The most common concussion symptoms are listed below. If you experience one or more of these symptoms after sustaining a hit to the head or body, you may have a concussion and you should be evaluated by a licensed health professional.

Concussion Signs Observed:

  • Can’t recall events prior to or after a hit or fall
  • Appears dazed or stunned
  • Forgets an instruction, is confused about an assignment or position, or is unsure of the game, score or opponent
  • Moves clumsily, or stumbles
  • Answers questions slowly
  • Loses consciousness (even briefly)
  • Shows mood, behavior or personality changes

Concussion Symptoms Reported:


  • Headache
  • Nausea or vomiting
  • Blurry or double vision
  • Dizziness or difficulty with balance
  • Sensitivity to light, noise or lots of sensory stimulation (for example, having difficulty in a crowded room)


  • Confusion
  • Difficulty concentrating
  • Problems remembering
  • Feeling foggy or slowed down


  • A strong emotional reaction to having been injured
  • Feeling sad or down
  • Decreased interest in hobbies
  • Irritability or moodiness
  • Nervousness
  • A desire to be isolated from other people or a concern about participating in community activities


  • Difficulty falling or staying asleep
  • Sleeping more or less than usual
  • Drowsiness

For more information, please visit uofmhealth.org

What to do if you think you have a concussion?

If you think an athlete has a concussion, remove the athlete from play immediately. The athlete should sit out of play the day of the injury and should not return to play until a licensed medical professional says he or she is symptom-free and safe to return.

Children or teens who return to play too soon—while the brain is still healing—are at greater chance for having a repeat concussion, worsening of current concussion or another injury.

For more information about concussions in athletes, please visit the Concussion in Athletes page of uofmhealth.org.

You can also visit the NeuroSport Clinic page to get more information on athletic concussion treatment or to make an appointment.

How long does it take for symptoms to appear?

Concussions vary by person and incident. Although signs and symptoms generally show up soon after the injury, the signs and symptoms of a concussion can take minutes, hours or even days to appear. It is important to continuously check for signs of a concussion right after the injury and a few days following the injury.

You should seek medical attention if you have symptoms of concussion.

Are there specific tests to diagnose a concussion?

There is no specific test to diagnose a concussion. A concussion cannot be seen on CT or MRI scans. Concussion remains a clinical diagnosis made by a health care professionals. A physical exam and thorough neurologic history are the best ways to diagnose a concussion.

How do you treat a concussion?

As soon as you suspect you may have sustained a concussion, seek immediate medical attention to determine your plan of care.

The University of Michigan is one of only a handful of comprehensive programs in the country dedicated to the neurological concerns of athletes through the multidisciplinary NeuroSport outpatient clinic.

To make an appointment with the NeuroSport outpatient clinic, please call 734-930-7400.

An appointment to see an expert in concussion management should be made so that an appropriate treatment plan can be put in place. Whether or not emergency care occurred, beginning outpatient care within 1–5 days of injury allows for an individualized treatment plan to be started.

During the first few days (0–3 days) after a concussion, rest is important. Although the symptom burden in the days following the injury may be quite limiting, as soon as symptoms allow, return to activities of daily living, light cognitive and physical activity should be undertaken. The amount of activity should be determined by a health care provider who has expertise in the care of concussion. There is evidence to suggest the complete restriction from normal activities of daily living leads to prolonged recovery. During the acute symptomatic phase, any activity that worsens symptoms should be limited or avoided.

Good hydration (approximately 60–80 fluid ounces of water or non-caffeinated beverages each day), proper diet and restful sleep are important in all stages of recovery from concussion.

As symptoms begin to improve, gradually increasing physical activity should be encouraged. Until recently, the recommendation had been to rest until asymptomatic. New studies, including one performed at Michigan NeuroSport, suggest that limited exercise during this time allows for quicker recovery from concussion. The type of exercise that is tolerated during this time is dynamic and varies from individual to individual based on symptom burden. Determining the appropriate type and amount of exercise is part of individualized care that should be guided by a health care professional.

How long does a concussion last?

Recovery is influenced by several factors. Generally, it is expected that symptoms in adults may resolve within 14 days. For children, symptoms may take up to 30 days to resolve.

How do I know if I can return to playing my sport?

A previously concussed athlete should only return to sports with the approval of a licensed health professional. The Centers for Disease Control and Prevention (CDC) and American College of Sports Medicine (ACSM) recommend a five-step return to play progression that should be supervised by a health care professional.

Is there any safety equipment that can reduce the risk of sustaining a concussion?

Wearing a helmet is imperative to help reduce the risk of a serious brain injury or skull fracture. However, helmets are not designed to prevent concussions. Researchers and helmet manufacturers are constantly improving helmets in order to make them as protective as possible, but there is no “concussion-proof” helmet.

What are the symptoms of a more serious brain injury?

In rare cases, a more serious brain injury can occur in which a collection of blood can form in or around the brain following a hard hit.

If you notice any of the following symptoms following a hard hit, call 9-11 and seek medical attention immediately.

  • Loss of consciousness for more than one minute
  • Increasing confusion or inability to stay awake
  • Repetitive vomiting
  • Seizure or convulsion
  • Severe or increasing headache
  • Severe neck pain
  • Weakness, tingling or burning in arms or legs
  • Persistent double vision
  • Increasingly restless, agitated or combative
What is post-concussive syndrome?

Historically, 10–30% of individuals have a recovery that is considered “longer than normal.” Some call this prolonged recovery Post-concussive syndrome.

Many factors likely play a role in the development of prolonged recovery. One main factor that may contribute to the development of prolonged recovery is the lack of appropriate recognition and treatment. In those suffering from prolonged recovery, it is critical to identify the factors causing symptoms and initiate treatment for them.

Are there any long-term effects of sustaining a concussion?

We are still learning what the long-term effects of concussion are. There is a growing concern that concussions or repetitive head impacts not severe enough to cause concussion (sub-concussive blows) may cause or be a risk factor for development of later in life complications.

It is clear, primarily from studies of retired boxers, that some individuals appear to have developed neurologic problems secondary to repetitive mild head trauma in their athletic careers. Researchers subsequently discovered microscopic brain changes in individuals exposed to repetitive mild head trauma, chronic traumatic encephalopathy (CTE).

CTE is a diagnosis that can only be made after death, and the consequences of CTE pathology in life are still unknown. The important issue of risk of long-term consequences in children who participate in contact and collision sports has been addressed in epidemiologic studies that did not identify long-term neurologic or psychiatric consequences.