A concussion is an injury to the brain caused by a blow or jolt to the head that disrupts the normal functioning of the brain. Concussions are usually not life-threatening. Since the brain is very complex, there is great variation in the signs and symptoms of a concussion. Some people lose consciousness; others never lose consciousness. Some symptoms may appear immediately, while others do not appear for several days or even weeks. Symptoms include:

• Headaches or neck pain that will not go away

• Difficulty with mental tasks such as remembering, concentrating, or making decisions

• Slowness in thinking, speaking, acting, or reading

• Getting lost or easily confused

• Feeling tired all of the time, having no energy or motivation

• Mood changes (feeling sad or angry for no reason)

• Changes in sleep patterns (sleeping a lot more or having a hard time sleeping)

• Light-headedness, dizziness, or loss of balance

• Urge to vomit (nausea)

• Increased sensitivity to lights, sounds, or distractions

• Blurred vision or eyes that tire easily

• Loss of sense of smell or taste

• Ringing in the ears