What Are the Long-Term Effects of a Concussion?

Concussions typically are mild traumatic brain injuries that occur after a fall or a blow to the head. In most cases, they are not life-threatening and a single concussion won't cause permanent brain damage. Although most symptoms of a concussion will resolve within a few weeks, some effects are chronic and can result in a condition called post-concussion syndrome.

This condition is characterized by symptoms that include memory and sleep problems, difficulty concentrating, and psychological effects, occurring more often in cases of repeated brain injury, making it especially concerning for competitive athletes.     

What Is a Concussion?

A concussion, also known as traumatic brain injury (TBI), is the result of trauma to the brain due to a fall or collision. The sudden jerking motions of the head and neck resulting from trauma cause the brain to twist and bounce inside the skull, immediately damaging its cells and surrounding structures. Though concussion is not as severe as other forms of TBI, and the symptoms are typically not life-threatening, this condition can become fatal.

When you have long-term effects of a concussion—those that persist for more than three weeks—you have what’s clinically known as post-concussion syndrome (PCS). Occurring in about 10%–25% of all concussion cases, PCS is the result of inflammation, altered blood flow, and disrupted brain cell structures due to the original injury.

Short-Term Effects

The common effects of a concussion typically arise minutes to hours after the blow or fall. In general, they last about two to three weeks before resolving on their own. These short-term symptoms include:

• Headache
• Nausea and vomiting
• Loss of consciousness
• Difficulty balancing and staying upright
• Blurry or doubled vision
• Ringing in the ears
• Sensitivity to light
• Sleep problems and fatigue

In addition, a concussion is often accompanied by neurological and psychological symptoms, such as:

• Confusion
• Difficulty with comprehension or concentration
• Depression and sadness
• Irritability, nervousness, and anxiousness
• The feeling of being in a “fog”
• Memory loss and challenges with paying attention

Infants and toddlers also can experience concussions, and, given the limitations in communication of children this age, diagnosis is much more difficult. Concussion in young children is characterized by:

• Bumps forming on the head
• Vomiting
• Irritability and being cranky
• Low appetite or an unwillingness to nurse
• Changes in sleep patterns
• Fussiness
• Blank stare

With infants or toddlers, it’s especially important to be vigilant about injuries. Don’t hesitate to call your pediatrician or get emergency help after a fall or suspected head injury.

Long-Term Effects

The longer-term effects of concussion, which typically last after immediate symptoms have receded, can arise within days or even hours of the fall or collision. These symptoms include:

• Difficulty concentrating
• Significant memory issues
• Irritability and changes in personality
• Light and noise sensitivity
• Disturbed sleep patterns
• Depression, anxiety, and other psychological issues
• Changes in smell and taste sensation

Most people who experience a concussion won’t have long-term symptoms, but the chances of developing them increase if you have had a concussion or another type of TBI in the past. One severe condition—an inflammation of the brain called chronic traumatic encephalopathy (CTE)—is associated with repeated concussions.  

Preventing Long-Term Injury

The key to preventing long-term problems and post-concussion syndrome is timely and proper care. Even if you (or a loved one) don’t require emergency care, the best thing you can do is to get medical attention within one to two days of the accident or fall.

Ways to prevent concussion include:

• Always wear your safety belt when traveling in a vehicle.
• When cycling or playing certain sports, wear an appropriate helmet.
• Use handrails when walking on stairs.
• Install safety gates by stairs for young children and toddlers.
• Add grab bars and nonslip mats in the bathroom.
• Improve lighting in the home and remove trip hazards.
• Strengthen neck muscles to help stabilize your head if in a fall.

By far the most important prevention tool is careful and exact adherence to post-concussion protocols. Reinjury of the brain before it’s fully recovered greatly increases the risk of chronic symptoms, permanent damage, and post-concussion syndrome. According to these conventions, athletes must stay away from activity until:

• Symptoms are absent during rest, physical activity, or mental tasks.
• Daily tasks, schooling, and work can be tolerated.
• Neurological and cognition test results post-concussion match those taken before the head injury or pass criteria set by the school or athletic board.
• Passing results are obtained during a physical exam and balance test.
• Full contact activity is cleared by a healthcare provider with expertise in concussion.

Caution should always be heeded with concussion. While most people will fully recover, problems can arise if the recovery period is rushed and parts of the brain that are still healing become injured again.

When to See a Doctor

Given how critical it is to get timely treatment for concussions, it’s absolutely essential to know what the signs are for when to see a doctor or get emergency help following a collision or fall. For adults, the criteria are:

• Worsening and lingering headache
• Continued numbness, weakness, loss of coordination, convulsions, or seizures
• Repeated vomiting and nausea
• Slurred speech or changes in behavior
• One pupil dilated, while the other is not
• Confusion, lack of recognition of faces, restlessness, and agitation
• Loss of consciousness, excessive drowsiness, and inability to wake up

In children, toddlers, and infants, call 911 if you see:

• Any or all of the above symptoms
• Inconsolable crying and behavior
• Loss of appetite or disinterest in nursing

When it comes to concussion, don’t hesitate and don’t delay in getting treatment. If you believe you or a loved one has experienced a concussion, get help as soon as possible. As with many conditions, the sooner you get help, the better off you’ll be.

Frequently Asked Questions

What are the long-term effects of concussion?

Arising anywhere from a couple hours to six weeks after the initial injury, they include:

• Cognitive issues, such as difficulty with concentration or memory
• Disrupted sleep, including trouble falling asleep, staying asleep, and feeling tired throughout the day
• Changes in mood or personality, irritability
• Trouble staying in balance
• Light and noise sensitivity
• Changed senses of taste and smell
• Depression, anxiety, and other mental health conditions

What percentage of people have long-term effects after a concussion?

Overall, about 10%–20% of people with concussions experience post-concussion syndrome and feel symptoms after three months. Nine out of 10 cases resolve within two weeks. That said, there's a good chance that concussions, in general, are being underreported, so overall rates may be higher.

What helps prevent long-term effects of a concussion?

Preventing the long-term effects of a concussion starts with reducing the chance of getting a head injury in the first place. Key steps to take include:

• Car safety: It's essential for everyone in a vehicle to use seat belts, and children should be strapped into age-appropriate car seats and booster seats.
• Helmets: Properly wearing helmets while bicycling, skating and skateboarding, riding on motorcycles, and taking part in contact sports can reduce your chances of getting a concussion.
• Home safety: Installing slip- and fall-prevention devices and surfaces on floors, railings, and stairs for children and adults can help prevent falls in the home.
• Safe play spaces: Making sure playgrounds have safe material and soft surfaces can help prevent childhood concussion.

Another step is proper post-concussion management. As your brain is healing, there's an increased chance of more severe effects—or experiencing another concussion—with reinjury. This involves:

• Not driving until cleared to do so by the doctor
• Getting prompt medical attention
• Not moving a person with a suspected concussion without medical help
• Getting plenty of sleep at night as well as naps during the day
• Remaining vigilant of symptoms throughout recovery
• Staying away from sports-related activities until cleared to return

Can an old head injury cause problems years later?

Yes, the more times you have a concussion, the greater the chance you can develop long-term or severe symptoms. Repeated TBIs can cause chronic traumatic encephalopathy (TCE), a progressive brain condition that is diagnosed only after death. This condition is characterized by:

• Changes in thinking, behavior, and emotions
• Aggression
• Depression and anxiety
• Personality and mood changes
• Motor symptoms, such as with Parkinson's disease or motor neuron disease

In addition, a history of concussion increases the chance of a case becoming fatal.

Can you die from a concussion?

Yes. While chances of dying from concussion are exceedingly rare, it can happen. In some cases, bleeding and inflammation in the brain, especially if untreated, is fatal. This is why careful observation is needed for the first 24–48 hours following brain injury. Get emergency help if symptoms become more pronounced and severe.