A concussion is a traumatic brain injury (TBI) that occurs when the brain moves quickly and back and forth inside your head, often as the result of a sudden blow to the head or a hard fall. This movement can injure your brain by setting off chemical changes or by damaging brain cells, causing a variety of symptoms to occur.
Concussions are considered “mild” brain injuries, but they should always be taken seriously and treated appropriately. It can take anywhere from several hours to a few days for the signs and symptoms of a concussion to appear, so it’s important to know what to look for if you or a loved one have recently experienced an injury that could cause a concussion.
Signs of a Concussion
There are four main categories of concussion symptoms that someone can experience: physical, cognitive, emotional, and sleep-related. However, sometimes people with a concussion—or other brain injury—can have trouble recognizing their own symptoms.
In such cases, a caregiver or loved one should keep an eye out for certain signs if a person mentions they hurt their head or experienced a brain injury. If you are a caregiver or loved one to someone, you may want to be mindful of the following signs of a concussion:
- Slow response to questions
- Confusion or forgetfulness
- Inability to remember what happened before or after injury
- A dazed or stunned appearance
- Loss of consciousness (though this only happens in about 10% of cases)
Physical effects, like headache, dizziness, nausea or vomiting, sensitivity to bright lights and loud noises, and difficulty maintaining balance are some of the more commonly-known symptoms of concussion.
Visual symptoms are also very common with concussions, affecting about 90% of people. These include:
- Double vision (or, seeing double)
- Blurry vision
- Difficulty focusing
- Trouble keeping track of objects with your eye
- Loss of depth perception
Because concussions are brain injuries, it’s common to experience cognitive or neurological (brain-related) symptoms. You might experience one or more of the following symptoms that can affect your thinking:
- Difficulty concentrating or focusing on tasks
- Having a hard time remembering things as easily
- Feeling confused, groggy, or disorientation
- Not being able to think clearly or having brain fog
Emotional symptoms aren’t as well known as some other categories of symptoms. As research on the emotional symptoms of concussions continues, experts have found evidence that people with a concussion may experience:
- Depression or sadness
- General changes in mood and behavior
If you’ve heard that you should never let a person with a suspected concussion fall asleep, that’s outdated advice. Before diagnostic testing was available to see if someone had a concussion, healthcare providers often recommended keeping someone awake for a period of time to monitor them for signs of bleeding in the brain.
Now, as long as a person has received treatment for a concussion, they are allowed—and, in fact, advised—to get some sleep. That said, sleep-related problems are still possible. These symptoms may include:
- Sleeping too much or too little
- Having trouble falling asleep
- Feeling very drowsy or fatigued
Symptoms in Children
Concussions are common among people over 75, children under age four, and young adults between the ages of 15 and 24. Older adults, babies, and toddlers are more likely to get concussions from slips and falls or bumps to the head, while teens and young adults are prone to concussions because of sports and athletics.
For older children, the signs and symptoms of a concussion are largely the same as they are in adults. But younger children may show additional symptoms such as:
- Changes in eating and sleeping habits
- Inconsolable crying
- Refusing to nurse or take a bottle
- Behavior changes at home or school
- Extreme emotional responses or tantrums
- Forgetting recently learned skills
- Loss of interest in favorite activities or toys
When to See a Healthcare Provider
If you or a loved one has experienced a brain injury, it’s important to visit a healthcare provider as soon as possible. This is especially the case if you or someone has fallen, felt a bump or blow to the head, been in a car accident, or experienced a sports injury.
However, some concussion symptoms are particularly urgent. If you or a loved one have any of the following symptoms, it’s critical to reach out for immediate care:
- A severe headache that doesn’t go away
- Weakness or numbness in the limbs
- Repeated vomiting
- Difficulty waking up
- Enlarged pupils or blurry vision
- Extreme or sudden changes in personality, mood, or behavior
- Constant crying and/or refusal to eat (in babies)
- Loss of consciousness for any length of time
Your or your loved one’s healthcare provider can get started on diagnostic testing immediately to figure out a treatment plan that works best to improve symptoms.
A Quick Review
While concussions are “mild” brain injuries, they still warrant medical attention and close monitoring until symptoms have resolved. When someone has a concussion, they might experience one or more physical, cognitive, emotional, and sleep-related symptoms.
Common symptoms of a concussion include headache, dizziness, trouble thinking or concentrating, mood changes, and changes in sleep. However, young children with a concussion can display additional symptoms such as excessive crying and loss of interest in their favorite activities.
Centers for Disease Control and Prevention. What is a concussion?
Centers for Disease Control and Prevention. Concussion signs and symptoms.
American Academy of Pediatrics. Concussions: What parents need to know.
Ferry, B, DeCastro, A. Concussion. In: StatPearls. StatPearls Publishing; 2022.
American Association of Neurological Surgeons. Concussion.
American Optometric Association. Concussions.
Concussion Legacy Foundation. What is a concussion?
BrainLine. Is it true that you should keep someone awake who has sustained a TBI?
BrainLine. Concussion symptoms in toddlers & babies.