DefinitionBy Mayo Clinic staff
A concussion is a traumatic brain injury that alters the way your brain functions. Effects are usually temporary, but can include problems with headache, concentration, memory, judgment, 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. Luckily, most concussive traumatic brain injuries are mild, and people usually recover fully.
SymptomsBy Mayo Clinic staff
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 most common symptoms after a concussive traumatic brain injury are headache, amnesia and confusion. 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:
- 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
- Nausea or vomiting
- Slurred speech
Some symptoms of concussions may be immediate or delayed in onset by hours or days after injury:
- 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
Seek emergency care for anyone who experiences a head injury and:
- A loss of consciousness lasting more than a minute
- Repeated vomiting
- Obvious difficulty with mental function or physical coordination
- Symptoms that worsen over time