Brain & Nervous System Head Trauma Concussions How to Tell If You Have a Concussion By Angelica Bottaro Updated on April 03, 2024 Medically reviewed by Brian M. Snelling, MD Print Table of Contents View All Table of Contents Symptoms Signs in Children Complications When to See a Doctor Frequently Asked Questions A concussion is a form of traumatic brain injury (TBI) that occurs after a blow or jolt to the head. This sudden movement of the head can cause the brain to bounce around or twist in the skull, creating chemical changes in your brain. A concussion can produce a temporary or permanent loss of brain function. It may be difficult to determine whether you have a concussion because the symptoms can vary from person to person. Infants and children can present with different signs and symptoms also. Signs and symptoms generally appear soon after the injury. However, you may not know how serious the injury is at first, and some symptoms may not be noticed for hours or even days. Verywell / Michela Buttignol Symptoms of a Concussion Following a bump, jolt, or blow to the head, you may experience a concussion. Signs of a concussion that may be observed in you by others include: Being unable to recall events that occur before or after the injuryAppearing to be stunned or dazedBeing unable to recall instructionsAppearing confusedDisplaying clumsy movementsBeing slow to answer questionsLosing consciousnessHaving mood, personality, or behavioral changes For the person experiencing the concussion, the above signs may not be obvious. But there are symptoms of a concussion you may experience that others may not pick up on, including: A headache or pressure in the head Balance issues Dizziness Double or blurry vision Nausea and vomiting Issues with remembering things or feeling confused Feeling like you can’t concentrate Feeling "off" or "down" Sluggishness, or having a hazy, foggy, or groggy feeling in your head Post-concussion syndrome describes a set of complex symptoms that includes headache, dizziness, neuropsychiatric symptoms, and cognitive impairment occurring after TBI. Concussion and Your Vision Signs in Young Children When a concussion happens in children or infants, they may have a difficult time communicating the symptoms they are experiencing. Because of this, parents should be aware of signs that their baby or toddler may have a concussion. The signs that your child has a concussion can include: CryingComplaining of head painBeing unable to sleep, or waking at nightHaving mood changes, such as uncontrollable laughter or crying or an increased temperBeing irritableVomitingHaving noticeable issues with concentrationHaving balance problemsBeing more sensitive to light or sound If you are present when your child hits their head, you should immediately check for signs of concussion. Symptoms may not appear right away, so you should monitor your child for at least 48 hours afterward. If symptoms come on during that time, the child needs to be evaluated by a physician immediately. Check on your child every one to two hours if they have a concussion. Complications A complication that could occur following a concussion is second-impact syndrome. It arises if a second concussion occurs before the first one fully heals. Second-impact syndrome can lead to fatal brain swelling. The risk of this complication is much higher in those who play sports, such as football or boxing. This is why it’s vital to always fully recover from a concussion prior to returning to normal activities. Other complications that can arise following a concussion include: Headaches Vertigo (a feeling of spinning and dizziness) Post-traumatic epilepsy (a seizure disorder) Depression, anxiety, or behavioral changes A specific type of brain degeneration known as chronic traumatic encephalopathy (CTE) Can You Sleep After You Hit Your Head or Get a Concussion? When to See a Doctor After a blow to the head, go to a hospital immediately if you have any of these symptoms: One pupil (the dark center of the eye) is larger than the otherCan't wake up or are excessively drowsyA worsening headache or one that persistsSlurring of speechFeelings of weakness or numbnessLoss of coordinationNausea or vomitingShaking or twitchingConfusion or unusual behaviorPassing out, even briefly Concussions Doctor Discussion Guide Download PDF Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Email Address Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. Summary A concussion can occur after a blow or trauma to your head. The signs observed by others and the symptoms experienced by the person with the concussion may be different. You may notice symptoms immediately following the injury or a few hours or even days afterward. If you suspect you or someone you're with, including a child, has a concussion, monitor for any changes in mood, vision, and cognitive function and seek help. A Word From Verywell Hitting your head or falling can be scary. Sometimes it causes no injuries other than a bump or bruise. At other times, it can be very serious. It’s always best to get any head injury looked at by a healthcare provider. A concussion is a serious condition that needs to be addressed as soon as possible. Knowing the signs and symptoms of a concussion in yourself or a loved one will help you seek prompt treatment. Getting adequate treatment soon after a concussion reduces the risk of complications and helps prevent prolonged symptoms. Yes. Although concussions are typically caused by a blow or bump to the head, they can also be caused by a fall or blow to the body that causes the head to jolt back and forth. If the force of the jolt is powerful enough, it can lead to a concussion. Frequently Asked Questions Do your pupils dilate if you have a concussion? Sometimes. Although pupil dilation isn’t always a reliable sign of a concussion, it can occur in some people. Pupil dilation following a concussion typically only occurs in one pupil, with that pupil appearing larger than the other. It could be a sign that the structure of the brain was damaged, and you should go to the emergency department immediately. Are there tests to tell you if you have a concussion? Yes. A concussion will typically be diagnosed using a physical exam, which involves testing vision, hearing, balance, coordination, reflexes, memory, and concentration. Other tests may need to be conducted, including an MRI (magnetic resonance imaging) or a CT scan (computed tomography scan) to check for changes in the brain.The Food and Drug Administration (FDA) recently approved a test called the Banyan BTI (Brain Trauma Indicator), a blood test designed for adults to measure levels of two protein biomarkers released from the brain into the bloodstream within 12 hours of the injury. How long after a head injury can concussion symptoms start? Concussion symptoms can begin immediately following a head injury, but they can also develop over the course of a few hours or even a few days. Can you get a concussion without hitting your head? Yes. Although concussions are typically caused by a blow or bump to the head, they can also be caused by a fall or blow to the body that causes the head to jolt back and forth. If the force of the jolt is powerful enough, it can lead to a concussion. 11 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. MedlinePlus. Concussion. Centers for Disease Control and Prevention. Concussion signs and symptoms. Polinder S, Cnossen MC, Real RGL, Covic A, Gorbunova A, Voormolen DC, Master CL, Haagsma JA, Diaz-Arrastia R, von Steinbuechel N. A Multidimensional Approach to Post-concussion Symptoms in Mild Traumatic Brain Injury. Front Neurol. 2018 Dec 19;9:1113. doi:10.3389/fneur.2018.01113 Corwin DJ, Grady MF, Joffe MD, Zonfrillo MR. Pediatric Mild Traumatic Brain Injury in the Acute Setting. Pediatr Emerg Care. 2017 Sep;33(9):643-649. doi:10.1097/PEC.0000000000001252 Nationwide Children's Hospital. A Parent's Guide to Concussions. American Association of Neurological Surgeons. Concussion. Tator CH. Concussions and their consequences: current diagnosis, management and prevention. CMAJ. 2013 Aug 6;185(11):975-979. doi:10.1503/cmaj.120039 Centers for Disease Control and Prevention. Concussion danger signs. Centers for Disease Control and Prevention. Facts about concussion and brain injury. Michigan University Health. Concussion Facts: 8 Common Misconceptions about Concussions. Medline Plus. Concussion Tests. By Angelica Bottaro Bottaro has a Bachelor of Science in Psychology and an Advanced Diploma in Journalism. She is based in Canada. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit