The signs and symptoms of a concussion can be subtle and may not be immediately apparent. Symptoms can last for days, weeks or even longer.

The two most common concussion symptoms are confusion and amnesia. The amnesia, which may or may not be preceded by a loss of consciousness, almost always involves the loss of memory of the impact that caused the concussion.

Signs and symptoms of a concussion may include:

• Confusion
• Amnesia
• Headache
• Dizziness
• Ringing in the ears
• Nausea or vomiting
• Slurred speech
• Fatigue

Some symptoms of concussions are not apparent until hours or days later. They include:

• Memory or concentration problems
• Sensitivity to light and noise
• Sleep disturbances
• Irritability
• Depression

Symptoms in children
Head trauma is very common in young children. But concussions can be difficult to recognize in infants and toddlers because they can't readily communicate how they feel. Nonverbal clues of a concussion may include:

• Listlessness, tiring easily
• Irritability, crankiness
• Change in eating or sleeping patterns
• Lack of interest in favorite toys
• Loss of balance, unsteady walking

When to see a doctor
While most concussions get better on their own, some blows to the head can cause more-serious injuries. Seek medical advice if you have any of the following symptoms:

• Prolonged headache or dizziness
• Vision or eye disturbances, including pupils that are bigger than normal (dilated pupils) or pupils of unequal sizes
• Nausea or vomiting
• Impaired balance
• Prolonged memory loss
• Ringing in the ears
• Loss of smell or taste

The American Academy of Pediatrics recommends that you call your child's doctor for advice if your child receives anything more than a light bump on the head.

Signs that a child who has a head injury needs medical attention include:

• Loss of consciousness
• Repeated vomiting
• Seizure (convulsion)
• Headache that gets worse over time
• Changes in your child's behavior, including irritability or difficulty waking
• Changes in your child's physical coordination, including stumbling or clumsiness
• Confusion
• Slurred speech
• Lasting or recurrent dizziness
• Blood or fluid discharge from the nose or ears
• A cut that won't stop bleeding after you've applied pressure for 10 minutes

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Your brain has the consistency of gelatin. It's cushioned from everyday jolts and bumps by the cerebrospinal fluid that it floats in, inside your skull. A violent blow to your head can cause your brain to slide forcefully against the inner wall of your skull. Even the sudden stop of a car crash can bounce your brain off the inside of your skull. This can result in bleeding in or around your brain and the tearing of nerve fibers.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Any blow to the head can cause a concussion. Falls and traffic accidents often involve concussions, with or without other injuries. Without proper safety equipment and supervision, student athletes may be at increased risk of concussions when playing football and other contact sports.

Concussions don't always involve head impact. Sudden acceleration or deceleration of the head — resulting from events such as a car crash or, in babies, being violently shaken — can cause a concussion. And anyone who has had a concussion is at higher risk of having concussions in the future.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Postconcussion syndrome, a poorly understood complication, causes concussion symptoms to last for weeks or months. People who have had a concussion also double their risk of developing epilepsy within the first five years after the injury.

There also is evidence that people who have had multiple concussions over the course of their lives experience cumulative neurological damage. A link between multiple concussions and the eventual development of Alzheimer's disease also has been suggested.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Seek emergency care for anyone who has had a head injury and has lost consciousness, is vomiting repeatedly, is having seizures or is having obvious difficulty with mental function or physical coordination.

Call your doctor if you have had a head injury and are experiencing ongoing nausea, pain, problems with physical coordination, or difficulties with memory, concentration or mood. If your child has received a head injury that concerns you, call your child's doctor immediately. Depending on the signs and symptoms, your doctor may recommend seeking immediate medical care.

Here's some information to help you get ready for and make the most of your medical appointment.

What you can do

• Be aware of any pre-appointment restrictions or instructions. At the time you make the appointment, be sure to ask if there are any steps you or your child should be following to encourage recovery or prevent re-injury. For example, if the office visit is because of a head injury from sports, ask whether it's safe to resume playing before the appointment.
• List any symptoms you or your child have been experiencing, and for how long.
• Write down key medical information, including other medical problems for which you or your child are being treated and any history of previous head injuries. Also write down the names of any medications, vitamins, supplements or other natural remedies you or your child are taking.
• Take a family member or friend along, if you are the one with the head injury. Sometimes it can be difficult to soak up all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor.

For concussion, some basic questions to ask your doctor include:

• How severe is the head injury?
• Is it a concussion?
• What kinds of tests are needed?
• What treatment approach do you recommend?
• How soon will symptoms begin to improve?
• What is the risk of future concussions?
• What is the risk of long-term complications?
• When will it be safe to return to competitive sports?
• When will it be safe to resume vigorous exercise?
• Is it safe to return to school or work?
• Is it safe to drive a car or operate power equipment?
• Should a specialist be consulted? What will that cost, and will my insurance cover seeing a specialist?
• Are there any brochures or other printed material that I can take home with me? What Web sites do you recommend?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor
Being ready to answer your doctor's questions may reserve time to go over any points you want to talk about in-depth.

You or your child should be prepared to answer the following questions about the injury and related signs and symptoms:

• Do you play contact sports?
• How did you sustain this injury?
• What symptoms did you experience immediately after the injury?
• Do you remember what happened right before and after the injury?
• Did you lose consciousness after the injury?
• Did you have seizures?
• Have you experienced nausea or vomiting since the injury?
• Have you had a headache? How soon after the injury did it start?
• Have you noticed any difficulty with physical coordination since the injury?
• Have you had any problems with memory or concentration since the injury?
• Have you noticed any sensitivity or problems with your vision and hearing?
• Have you had any mood changes, including irritability, anxiety, depression?
• Have you felt lethargic or easily fatigued since the injury?
• Are you having trouble sleeping, or waking from sleep?
• Have you noticed changes in your sense of smell or taste?
• Do you have any dizziness or vertigo?
• What other signs or symptoms are you concerned about?
• Have you had any previous head injuries?

What you can do in the meantime
Rest as much as possible in the time leading up to your appointment. If you have a headache, take acetaminophen (Tylenol, others). Don't take aspirin, ibuprofen (Advil, Motrin, others) or other nonsteroidal anti-inflammatory drugs (NSAIDs) if you suspect you've had a concussion. They may increase the risk of bleeding.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Diagnosing a concussion is usually straightforward. If a blow to your head has knocked you out or left you dazed, you've had a concussion. It's more difficult, however, to determine whether the blow has caused potentially serious bleeding or swelling in your skull. Signs and symptoms of these injuries may not appear until hours or days after the injury.

After your doctor asks detailed questions about your accident, he or she may perform a neurological exam. This evaluation includes checking your:

• Memory and concentration
• Vision
• Hearing
• Balance
• Coordination
• Reflexes

A computerized tomography (CT) scan is the standard test to assess postconcussion damage. A CT scanner takes multiple cross-sectional X-rays and combines all the resulting images to produce detailed, two-dimensional images of your skull and brain. During the procedure, you lie still on a table that slides through a large, doughnut-shaped X-ray machine. The scan is painless and generally takes less than 10 minutes.

Not every concussion requires a CT scan, but the test is usually done as a precaution if there's a chance your injury is more severe than your immediate condition suggests. You're more likely to need a scan if you:

• Are age 65 or older
• Fell from a height of more than 3 feet (1 meter)
• Had a motor vehicle crash
• Are under the influence of alcohol or drugs
• Are unable to recall the accident for at least 30 minutes after it occurred
• Have persistent trouble with short-term memory — that is, retaining new information — after you've completely regained consciousness
• Vomited
• Had a seizure
• Suffered bruises, scrapes or cuts on your head and neck
• Fractured your skull

You may need to be hospitalized overnight for observation after a concussion. If your doctor says it's OK for you to be observed at home, someone should check on you periodically for at least 24 hours. You may need to be awakened every two hours to make sure you can be roused to normal consciousness.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Rest is the best recovery technique. Healing takes time. For headaches, use acetaminophen (Tylenol, others). Don't take aspirin, ibuprofen (Advil, Motrin, others) and other nonsteroidal anti-inflammatory drugs (NSAIDs), as these medications can increase the risk of bleeding.

If you or your child sustained a concussion while playing competitive sports, ask your doctor or your child's sideline doctor when it is safe to return to play. Resuming sports too soon increases the risk of a second concussion and of lasting, potentially fatal brain injury.

No one should return to play or vigorous activity while signs or symptoms of a concussion are present. If signs or symptoms lasted 15 minutes or longer or included loss of consciousness or amnesia, it's not safe to return to play for at least one week.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

The following tips may help you to prevent or minimize your risk of head injury:

• Wear a helmet during recreational activities. When bicycling, motorcycling, skiing, horseback riding, skating or engaging in any recreational activity that may result in head injury, wear protective headgear.
• Buckle your seat belt. Wearing a seat belt may prevent serious injury, including an injury to your head, during a traffic accident.
• Make your home fallproof. Keep your home well lit and your floors free of clutter — meaning anything that might cause you to trip and fall. Falls around the home are the leading cause of head injury for infants, toddlers and older adults.
• Protect your children. To help lessen the risk of head injuries to your children, pad countertops and edges of tables, block off stairways and install window guards. Don't let your child use sporting equipment or play sports that aren't suitable for their age.
• Use caution in and around swimming areas. Don't dive into water less than 9 feet (3 meters) deep. Read and follow posted safety rules at water parks and swimming pools.
• Wear sensible shoes. If you're older, wear thinner, hard-soled, flat shoes. Resilient-soled athletic shoes may impair your balance and contribute to falls. Avoid wearing high heels, sandals with light straps, or shoes that are either too slippery or too sticky.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.