It is not always easy to know if someone has a concussion. You don't have to pass out (lose consciousness) to have a concussion.

Symptoms of a concussion range from mild to severe and can last for hours, days, weeks, or even months. If you have multiple or repeated concussions, you may have more severe symptoms that can last longer. And it may take longer to recover. If you notice any symptoms of a concussion, contact your doctor.

Symptoms of a concussion fit into four main categories:

• Thinking and remembering
  • Not thinking clearly
  • Feeling slowed down
  • Not being able to concentrate
  • Not being able to remember new information
• Physical
  • Nausea and vomiting
  • Headache
  • Fuzzy or blurry vision
  • Dizziness
  • Sensitivity to light or noise
  • Balance problems
  • Feeling tired or having no energy
• Emotional and mood
  • Easily upset or angered
  • Sad
  • Nervous or anxious
  • More emotional
• Sleep
  • Sleeping more than usual
  • Sleeping less than usual
  • Having a hard time falling asleep

Young children can have the same symptoms of a concussion as older children and adults. But sometimes it can be hard to tell if a small child has a concussion. Young children may also have symptoms like:

• Crying more than usual.
• A headache that does not go away.
• Changes in the way they play or act.
• Changes in the way they nurse, eat, or sleep.
• Being upset easily or having more temper tantrums.
• A sad mood.
• Lack of interest in their usual activities or favorite toys.
• Loss of new skills, such as toilet training.
• Loss of balance and trouble walking.
• Not being able to pay attention.

Concussions in older adults can also be dangerous. This is because concussions in older adults are often missed. If you are caring for an older adult who has had a fall, check for symptoms of a concussion. Signs of a serious problem include a headache that gets worse, increasing confusion, or both. See a doctor right away if you notice these signs. If you are caring for an older adult who takes a blood thinner and who has had a fall, take them to a doctor right away, even if you don't see any symptoms of a concussion.

If you've had a concussion, you need to see a doctor. They will ask questions and do tests to check your thinking, memory, strength, balance, and reflexes. An imaging test, such as a CT scan or an MRI, may be done to check for a brain injury.

After seeing a doctor, most people can go home. Others need to be watched in the hospital. Rest can help you recover. Get plenty of sleep, avoid alcohol and drugs, and don't do activities that are physically or mentally demanding. Don't return to sports or activities until the doctor says it's okay.