A concussion is a traumatic brain injury that alters the way your brain functions. Effects are usually temporary but can include headaches and problems with concentration, memory, balance and coordination.
Although concussions usually are caused by a blow to the head, they can also occur when the head and upper body are violently shaken. These injuries can cause a loss of consciousness, but most concussions do not. Because of this, some people have concussions and don’t realize it.
Concussions are common, particularly if you play a contact sport, such as football. But every concussion injures your brain to some extent. This injury needs time and rest to heal properly. Most concussive traumatic brain injuries are mild, and people usually recover fully.
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.
Common symptoms after a concussive traumatic brain injury are headache, loss of memory (amnesia) and confusion. The amnesia, which may or may not follow a loss of consciousness, usually involves the loss of memory of the event that caused the concussion.
Signs and symptoms of a concussion may include:
- Headache or a feeling of pressure in the head
- Temporary loss of consciousness
- Confusion or feeling as if in a fog
- Amnesia surrounding the traumatic event
- Dizziness or “seeing stars”
- Ringing in the ears
- Slurred speech
- Delayed response to questions
- Appearing dazed
Some symptoms of concussions may be immediate or delayed in onset by hours or days after injury, such as:
- Concentration and memory complaints
- Irritability and other personality changes
- Sensitivity to light and noise
- Sleep disturbances
- Psychological adjustment problems and depression
- Disorders of taste and smell
Symptoms in children
Head trauma is very common in young children. But concussions can be difficult to recognize in infants and toddlers because they may not be able to describe how they feel. Nonverbal clues of a concussion may include:
- Appearing dazed
- Listlessness and tiring easily
- Irritability and crankiness
- Loss of balance and unsteady walking
- Crying excessively
- Change in eating or sleeping patterns
- Lack of interest in favorite toys
Your brain has the consistency of gelatin. It’s cushioned from everyday jolts and bumps by cerebrospinal fluid inside your skull. A violent blow to your head and neck or upper body can cause your brain to slide back and forth forcefully against the inner walls of your skull.
Sudden acceleration or deceleration of the head, resulting from certain events such as a car crash or being violently shaken, also can cause brain injury.
These injuries affect brain function, usually for a brief period, resulting in signs and symptoms of concussion.
A brain injury of this sort may lead to bleeding in or around your brain, causing symptoms such as prolonged drowsiness and confusion that may develop right away or later.
Such bleeding in your brain can be fatal. That’s why anyone who experiences a brain injury needs monitoring in the hours afterward and emergency care if symptoms worsen.
Factors that may increase your risk of a concussion include:
- Participating in a high-risk sport, such as football, hockey, soccer, rugby, boxing or other contact sport; the risk is further increased if there’s a lack of proper safety equipment and supervision
- Being involved in a motor vehicle collision
- Being involved in a pedestrian or bicycle accident
- Being a soldier involved in combat
- Being a victim of physical abuse
- Falling, especially in young children and older adults
- Having had a previous concussion
Potential complications of concussion include:
- Epilepsy. People who have had a concussion double their risk of developing epilepsy within the first five years after the injury.
- Cumulative effects of multiple brain injuries. Evidence exists indicating that people who have had multiple concussive brain injuries over the course of their lives may acquire lasting, and even progressive, impairment that limits their ability to function.
- Postconcussion syndrome. Some people begin having postconcussion symptoms — such as headaches, dizziness and thinking difficulties — a few days after a concussion. Symptoms may continue for weeks to a few months after a concussion.
- Post-traumatic headaches. Some people experience headaches within a week to a few months after a brain injury.
- Post-traumatic vertigo. Some people experience a sense of spinning or dizziness for days, week or months after a brain injury.
- Second impact syndrome. Experiencing a second concussion before signs and symptoms of a first concussion have resolved may result in rapid and usually fatal brain swelling.
After a concussion, the levels of brain chemicals are altered. It usually takes about a week for these levels to stabilize again. However, recovery time is variable, and it’s important for athletes never to return to sports while they’re still experiencing signs and symptoms of concussion.
A blow to your head, neck or upper body can cause a concussion, which may include symptoms such as a headache, dizziness, nausea or loss of consciousness. If you suspect you or your child has had a concussion, contact your doctor.
Your doctor will evaluate your signs and symptoms, review your medical history, and conduct a neurological examination. Signs and symptoms of a concussion may not appear until hours or days after the injury.
Tests your doctor may perform or recommend include:
After your doctor asks detailed questions about your injury, he or she may perform a neurological examination. This evaluation includes checking your:
- Strength and sensation
Your doctor may conduct several tests to evaluate your thinking (cognitive) skills during a neurological examination. Testing may evaluate several factors, including your:
- Ability to recall information
Brain imaging may be recommended for some people with symptoms such as severe headaches, seizures, repeated vomiting or symptoms that are becoming worse. Brain imaging may determine whether the injury is severe and has caused bleeding or swelling in your skull.
A cranial computerized tomography (CT) scan is the standard test to assess the brain right after injury. A CT scan uses a series of X-rays to obtain cross-sectional images of your skull and brain.
Magnetic resonance imaging may be used to view bleeding in your brain or to diagnose complications that may occur after a concussion.
An MRI uses powerful magnets and radio waves to produce detailed images of your brain.
You may need to be hospitalized overnight for observation after a concussion.
If your doctor agrees that you may be observed at home, someone should stay with you and check on you for at least 24 hours to ensure your symptoms aren’t worsening. Your caregiver may need to awaken you regularly to make sure you can awaken normally.
Rest is the most appropriate way to allow your brain to recover from a concussion. Your doctor will recommend that you physically and mentally rest to recover from a concussion.
This means avoiding general physical exertion, including sports or any vigorous activities, until you have no symptoms.
This rest also includes limiting activities that require thinking and mental concentration, such as playing video games, watching TV, schoolwork, reading, texting or using a computer.
Your doctor may recommend that you have shortened school day or workdays, take breaks during the day, or have reduced school workloads or work assignments as you recover from a concussion.
As your symptoms improve, you may gradually add more activities that involve thinking, such as doing more schoolwork or work assignments, or increasing your time spent at school or work.
For headaches, try taking a pain reliever such as acetaminophen (Tylenol, others). Avoid other pain relievers such as ibuprofen (Advil, Motrin IB, others) and aspirin, as there’s a possibility these medications may increase the risk of bleeding.
If you or your child sustained a concussion while playing competitive sports, ask your doctor or your child’s 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.
Evidence is emerging that some people who have had multiple concussions over the course of their lives are at greater risk of developing lasting, and even progressive, impairment that limits their ability to function.
No one should return to play or vigorous activity while signs or symptoms of a concussion are present.
Experts recommend that adults, children and adolescents not return to play on the same day as the injury.