A concussion is a type of traumatic brain injury (TBI). This injury is caused by a blow to the head, which makes the brain move back and forth within the skull. 

Even though a concussion is referred to as a “mild” brain injury, concussions can cause long-term health problems, especially if left untreated. It’s important to recognize the symptoms of a concussion and to seek immediate treatment if you believe you or someone you know has a concussion.

This guide from HealthTap breaks down what a concussion is, how it is treated, what happens if it’s not addressed quickly enough, and other common symptoms associated with this type of head injury. 

What is a concussion?

A concussion is a type of mild traumatic brain injury caused by a blow or jolt to the head or body, causing the brain to forcefully get pushed around in the skull.

A type of fluid called cerebrospinal fluid (CSF) cushions the brain from making firm contact with the skull on a day-to-day basis, but in a concussion, the brain moves too forcefully for the CSF to cushion, causing a brain-to-skull collision. 

A concussion can trigger chemical changes in the brain, such as how the brain cells communicate with each other. In some cases, a concussion can permanent brain damage because of damage to the brain cells. 

Most often, people think of sports-related concussions when they hear the term — it’s no surprise since professional athletes experience a higher rate of concussions than the rest of the population does. However, anyone can suffer from a concussion caused by head trauma, whether from falls (especially in the elderly), assault, recreational sports like football, basketball, or hockey, motor vehicle accidents (especially in the case of whiplash), or any other event that causes impact to the head.  

What’s more, a direct blow to the head isn’t necessary for a concussion to happen. Any event that forcefully shakes up the brain can be enough to cause brain trauma. 

Loss of consciousness is not a necessary part of a concussion, either. Most people with a concussion never lose consciousness. In fact, some people aren’t even aware that they’ve had a concussion — they just feel that something is “off,” whether with their reaction time or even mild personality changes.  

A concussion may be termed a “mild” traumatic brain injury; however, there is nothing mild about it. Those who suffered from a concussion may go on to develop long-term effects, such as lack of concentration, memory loss, and mood changes. Even in the short-term, a concussion can make it hard to focus on work or school and lead to impaired performance. 

What are the symptoms of a concussion?

The symptoms of a concussion fall into four categories:

1. Cognitive
   People with a concussion may feel confused, be unable to remember what happened immediately after their concussion, and can feel that their thinking is “foggy.” 

2. Emotional
   Changes in mood, such as increased nervousness, sadness, and irritability, can happen after a concussion. 

3. Physical
   Extreme fatigue can follow a concussion. Another common symptom is sensitivity to light or sound. 

4. Sleep Changes
   A concussion can make it harder to fall or stay asleep. 

One thing to keep in mind is that symptoms of a concussion can vastly vary between people. What’s more, some people may not notice any symptoms for days or weeks after their injury, while others may be slow to really recognize their symptoms. 

A medical evaluation by a healthcare provider is necessary anytime a concussion-like injury takes place. 

How is a concussion treated?

People with a concussion should be promptly evaluated by a doctor. A visit to a primary care doctor, urgent care clinic, or an emergency room for proper concussion diagnosis and concussion treatment can make a big difference in the long-term. In some cases, an overnight hospital stay may be required. 

To diagnose a concussion, a doctor will usually perform a test called a “neurocognitive assessment.” This type of test looks at learning, memory, focus, and reaction time. 

To rule out other types of brain injury, an imaging test of the brain called a CT scan may be completed. This is like an enhanced X-ray that looks at the skull and brain to make sure that everything looks as it should. If further observation in the hospital is not needed, then the doctor will typically send the patient home with instructions for recovery and, if necessary, pain medication. 

Rest — both mental and physical — is the first step in healing. This helps the brain to relax, which can aid the healing process. Taking time off from school or work is usually advised by the treating doctor. A concussion makes achieving daily activities a lot tougher than usual, due to a lack of focus, increased fatigue, and mood changes. 

Allow ample time to rest and recover. Trying to “tough it out” can make things worse in the long run. 

After recovering from a concussion, preventing another concussion from occurring becomes doubly important. Being exposed to multiple concussions significantly increases the risk of long-term problems, such as memory loss, lack of focus, and chronic headaches. Physical problems may also occur, such as dizziness and vertigo. 

What happens if a concussion is left untreated?  

A concussion is a serious condition that can have long-term effects if left untreated. 

Right after a concussion, people are at a much higher risk for another injury. Dizziness, vertigo, or loss of balance can lead to a fall, increasing the risk of further damage to the brain. 

Even if injury does not occur, failing to see a doctor for an evaluation and trying to battle with the symptoms can lead to various cognitive, emotional, and physical effects, making daily life a struggle. 

In some cases, an untreated concussion can lead to post-concussion syndrome. While it’s usual (and expected) to experience some symptoms after a concussion, in post-concussion syndrome, the symptoms can last months or even years. 

Researchers don’t have a full picture of concussions because it is an “invisible” injury. Unlike a broken bone, a concussion may not be visible on a brain scan, which is why it’s so important to pay attention to symptoms and see a doctor for an assessment if anything feels “off.” 

How is a concussion assessed?

There is no simple physical test that can diagnose a concussion, so doctors rely on a type of test called a “neurocognitive assessment.” These are essentially questions asked by the doctor that evaluate a person’s memory, focus, and reflexes. Some contact sport coaches and trainers will even perform this assessment as soon as the injury occurs.

There are a few tests that are used to assess a concussion. One of the quickest tests is called the standardized assessment of concussion (SAC), which takes about five minutes to complete. The SAC looks at a person’s orientation in time and space, their immediate memory, their neurologic function, their ability to focus, and their short-term memory. 

The SAC includes short-term tests like asking about the date and time, and checking general coordination. Although short, it’s a comprehensive test that looks at all components of a concussion. 

Another concussion test commonly used is called the Sports Concussion Assessment Tool 5 (SCAT 5). This test includes everything in the SAC test as well as a balance assessment, an evaluation of the spine, and several other factors. It takes about 15 minutes to complete. 

These tests on their own aren’t a substitute for a doctor’s medical evaluation. Instead, they’re used to look at the potential for and severity of a concussion. Only a doctor can rule out a concussion. 

Concussion symptom checker 

Concussion symptoms differ from person to person. This list of symptoms can help provide a reference point to gauge concussion severity, and is not a substitute for an evaluation by a medical professional. 

The following are potential signs of a concussion.

• Headache.

• Nausea or vomiting.

• Blurry vision.

• Sensitivity to light or sound.

• Balance problems like dizziness or vertigo.

• Numbness or tingling in the body.

• Reduced brain function or "brain fog.”

• Memory problems. 

• Difficulty concentrating.

• Low energy.

• Drowsiness.

• Slurred speech.

• Sleep problems.

• Nervousness.

• Sadness.

• Irritability.

If someone experiences multiple symptoms, a concussion is usually likely. However, it’s also possible to experience very few of these symptoms (or none at all) and still have a concussion. 

Get evaluated for a concussion immediately 

While a concussion is considered a mild traumatic brain injury, it shouldn’t be taken lightly. If a concussion isn’t treated, it can lead to long-term problems, such as memory loss, reduced concentration, mood changes, and trouble maintaining balance.

If a person suspects they have a minor concussion, HealthTap can help connect them with a healthcare professional for evaluation. With our secure online platform, they can meet with an urgent care doctor from the comfort of their own home. The online doctor can help them decide whether or not they should go get an in-person evaluation. A person suspecting worse than just a minor concussion usually should seek in-person medical attention as soon as possible.