Symptoms of a concussion can be subtle and may not show up immediately. Symptoms can last for days, weeks or even longer. Here are some common symptoms of a concussion:

• Headache
• Nausea or vomiting
• Balance problems or dizziness, or double or blurry vision
• Bothered by light or noise
• Feeling sluggish, hazy, foggy, or groggy
• Confusion, or concentration or memory problems
• Just not “feeling right,” or “feeling down”
• Loss of consciousness after the head injury
• Periods of memory loss
• Disturbances in vision, such as "seeing stars" or blurry vision
• A period of confusion, a blank expression, or a delay in answering questions immediately after the head injury

Symptoms of a concussion can be mild to severe, and in some cases, emergency treatment may be needed. Its important to seek medical attention immediately after a concussion if you or someone you know has these symptoms:

• Loss of consciousness
• Headache that’s getting worse, lasts for a long time, or is severe
• Confusion
• Extreme sleepiness or trouble waking up
• Vomiting
• Weakness, numbness, or trouble walking or talking
• Seizure or convulsion (where the arms and legs shake uncontrollably)
• Any other sudden change in thinking or behavior

If you or someone you know has concussion symptoms that last more than two weeks, consider seeing a doctor. These can include more serious symptoms of concussion or TBI, such as ongoing headaches, vertigo, and behavioral changes.