CTE: Early Signs, Symptoms, Risk Factors & What We Know

Oct 6

If you have had multiple concussions or years of repetitive head impacts, you may have wondered:

Could I have CTE?

It is an understandable concern. Chronic traumatic encephalopathy (CTE) has received increasing attention as researchers have learned more about the long-term effects of repetitive head impacts in athletes, military personnel, and others exposed to repeated trauma to the head.

But there is an important distinction that is often lost in discussions about CTE:

Having concussion symptoms, memory problems, headaches, mood changes, or other neurological symptoms does not mean that you have CTE.

CTE is a specific form of neurodegenerative brain pathology associated with abnormal accumulation of the protein tau. At this point, CTE can only be definitively diagnosed by examining brain tissue after death. Researchers are actively working to develop ways to identify CTE during life.

That means if you are experiencing symptoms now, the more useful question is not simply, "Do I have CTE?"

It is: "What is causing my symptoms, and what can I do about them?"

What Is CTE?

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease characterized by a distinctive pattern of abnormal tau protein accumulation in the brain.

CTE has been associated with repetitive head impacts, including impacts that may or may not cause a diagnosed concussion. Research has found a relationship between cumulative exposure to repetitive head impacts and the likelihood of CTE pathology, particularly in people with long-term exposure to contact and collision sports.

However, repetitive head impacts do not affect every person in exactly the same way, and not everyone exposed to repeated head impacts develops CTE.

Researchers are still studying why some people develop CTE pathology while others do not and how factors such as the amount, frequency, force, and duration of repetitive head impacts may influence risk.

One important finding from recent research is that repetitive head impacts can produce brain changes even in people who do not have CTE. A 2025 study of former contact-sport athletes found evidence of neuronal loss, inflammation, and vascular changes associated with repetitive head-impact exposure, including in athletes without CTE pathology.

In other words, CTE is only one potential long-term consequence of repetitive head impacts.

What Are the Early Signs of CTE?

This is where CTE can become confusing. There is no simple list of symptoms that allows someone to look at their symptoms and determine that they have CTE.

Symptoms associated with CTE can include changes involving:

Memory and thinking
Executive functioning and decision-making
Mood
Behavior
Impulse control
Sleep
Movement and coordination

However, many of these symptoms are nonspecific. They can occur with concussion, post-concussion syndrome, sleep disorders, depression or anxiety, migraine, medication effects, autonomic dysfunction, vestibular problems, other neurological conditions, and many other causes.

Therefore, headaches, brain fog, irritability, anxiety, depression, poor sleep, or memory problems are not proof of CTE.

The clinical research criteria for traumatic encephalopathy syndrome (TES) specifically require substantial exposure to repetitive head impacts along with particular patterns of progressive cognitive and/or neurobehavioral changes, while also considering whether another medical, neurological, or psychiatric condition better explains the symptoms.

That distinction matters.

CTE Symptoms: What Researchers Have Observed

Research into people with confirmed CTE pathology has identified several broad categories of symptoms.

Cognitive Changes

These may include:

Increasing difficulty with memory
Problems with attention
Difficulty with planning or organization
Problems with executive functioning
Slowed thinking
Increasing difficulty managing everyday tasks

Importantly, occasional forgetfulness or brain fog does not mean you have CTE. Almost everyone experiences these symptoms at times, and they can occur for many different reasons.

Mood and Behavioral Changes

Some people with CTE pathology have experienced:

Irritability
Depression
Anxiety
Emotional dysregulation
Impulsivity
Changes in behavior
Difficulty controlling anger

Again, these symptoms are not unique to CTE. A person experiencing anxiety or irritability after a concussion should not assume that these symptoms represent CTE. There are many potentially treatable contributors to these symptoms.

Movement Problems

In more advanced disease, researchers have observed neurological changes involving movement, balance, coordination, stiffness, and other motor functions.

These symptoms are different from the dizziness, balance problems, and exercise intolerance commonly experienced during concussion recovery.

Sleep Problems

Sleep disturbances have also been reported in people with CTE pathology.

But poor sleep is extremely common after concussion and in many other medical conditions, so sleep problems alone are not an indication of CTE.

Can CTE Be Diagnosed While You Are Alive?

Not definitively. This is one of the most important things to understand about CTE.

At present, CTE can only be definitively confirmed by examining brain tissue after death. Researchers are working on potential biomarkers and imaging techniques that could eventually allow CTE to be identified during life, but those tools are still being studied.

Recent NIH-funded research is helping clarify which symptoms are actually associated with CTE. A 2026 study found that severe CTE was strongly associated with dementia and cognitive and functional impairment, while milder CTE was not associated with these symptoms. Interestingly, mood and behavioral symptoms were not associated with CTE stage.

There is an important distinction between:

CTE
A neuropathological diagnosis based on characteristic changes in brain tissue.

and

Traumatic Encephalopathy Syndrome (TES)
A clinical research syndrome used to describe a particular combination of repetitive head-impact exposure and progressive cognitive or neurobehavioral symptoms.

TES does not mean that a person has definitively been diagnosed with CTE. The NINDS consensus criteria were developed primarily to advance research into the relationship between clinical symptoms and CTE pathology.

So if someone tells you that your headaches, memory problems, depression, or brain fog prove that you have CTE, that is not scientifically accurate.

Does Having Multiple Concussions Mean You Will Develop CTE?

No.

Multiple concussions are not the same thing as a diagnosis of CTE. Current research suggests that the relationship between CTE and repetitive head impacts is more complicated than simply counting the number of diagnosed concussions.

In football research, for example, cumulative exposure to repetitive head impacts has been strongly associated with CTE pathology, and researchers have found that the force and characteristics of those impacts may matter as well.

This is one reason the term repetitive head impacts is important.

A person can experience repeated impacts without experiencing obvious concussion symptoms after every impact.

At the same time, not everyone who experiences repetitive head impacts develops CTE.

Researchers are still investigating why.

What About CTE in Amateur Athletes?

CTE research is not limited to professional athletes.

Researchers have studied former amateur and collegiate athletes as well as professional athletes and military personnel.

Recent research has also emphasized that the effects of repetitive head impacts can occur before CTE pathology is present. A 2025 Boston University study found evidence of brain cell loss, inflammation, and vascular injury in young former contact-sport athletes, including some who did not have CTE.

This is important for amateur athletes and parents to understand.

The goal should not be to wait until someone develops a neurological disease.

The goal is to reduce unnecessary repetitive head impacts, take concussion seriously, and address neurological symptoms when they occur.

Can You Prevent CTE?

There is currently no guaranteed way to prevent CTE.

However, reducing exposure to repetitive head impacts is a logical strategy for reducing potential long-term risk.

That can include:

Reducing unnecessary exposure to repeated head impacts
Taking concussion symptoms seriously
Properly evaluating symptoms after a head injury
Following appropriate return-to-sport progression
Addressing persistent symptoms rather than simply ignoring them
Making informed decisions about sports and activities involving repeated head impacts

Protective equipment can reduce certain types of injury, but no helmet can eliminate the risk of concussion or CTE. Similarly, there is no evidence that simply following a concussion protocol guarantees that someone will not develop CTE. The science surrounding prevention is still evolving.

What Should You Do If You Have Persistent Symptoms After Concussion?

This is where the CTE conversation becomes particularly important. If you are experiencing ongoing headaches, dizziness, brain fog, fatigue, exercise intolerance, visual problems, sleep problems, neck pain, or difficulty tolerating busy environments after a concussion, do not assume that you have CTE. Persistent concussion symptoms can have multiple underlying contributors, many of which can be evaluated and treated.

For example, persistent symptoms may involve:

Vestibular dysfunction
Visual or oculomotor dysfunction
Autonomic nervous-system dysfunction
Cervical dysfunction
Exercise intolerance
Migraine
Sleep disruption
Poor regulation of the nervous system
Problems with balance or motion tolerance

The important step is to determine what is contributing to your symptoms and address those systems directly. That is very different from simply trying to mask symptoms or waiting for them to disappear.

Can Concussion Symptoms Years Later Be Treated?

Yes.

Having symptoms long after a concussion does not automatically mean that you have CTE or that nothing can be done. Persistent symptoms deserve a proper evaluation to determine what is actually driving them.

For example, someone who feels dizzy when walking through a grocery store may have a vestibular or visual problem.

Someone who becomes exhausted or lightheaded with exercise may have autonomic dysfunction or impaired exercise tolerance.

Someone with persistent headaches may have a combination of cervical, vestibular, visual, migraine, or other contributing factors.

These are very different problems, and they require different treatment strategies.

The goal is to identify the underlying contributors to the symptoms and treat them—not simply label the symptoms as "CTE."

What About People Who Are Worried They Already Have CTE?

If you have a history of repeated head impacts and are noticing progressive changes in memory, thinking, behavior, or function, it is reasonable to seek a comprehensive medical evaluation. That evaluation may include a detailed history, neurological examination, cognitive assessment, review of medications and sleep, and evaluation for other conditions that could explain the symptoms. A clinician can help determine whether your symptoms fit another, potentially treatable condition or whether further neurological evaluation is appropriate. And if your symptoms are primarily persistent concussion symptoms, a concussion-focused physical therapy evaluation can help identify vestibular, visual, cervical, autonomic, balance, and exercise-related contributors.

The Most Important Takeaway About CTE

CTE is a serious area of neurological research, and what scientists know about repetitive head impacts continues to evolve. But there is a huge difference between:

"I have symptoms that I am worried could be CTE"

and

"I have CTE."

Symptoms such as brain fog, headaches, dizziness, fatigue, poor sleep, anxiety, depression, irritability, or memory problems are not enough to diagnose CTE. At the same time, persistent neurological symptoms should not simply be ignored. If you are struggling after a concussion, there are many systems that can be evaluated and treated today, regardless of what future research may tell us about CTE.

What You Can Do Now

If you have experienced repeated head impacts, focus on the things that are within your control:

Reduce unnecessary repetitive head impacts.

Take new concussion symptoms seriously.

Get evaluated when symptoms persist.

Address sleep, exercise tolerance, vestibular function, vision, the neck, and autonomic function when they are contributing to symptoms.

Don't assume that persistent symptoms automatically mean CTE.

And don't assume that nothing can be done simply because CTE cannot currently be diagnosed during life.

Research into CTE is moving quickly. In the meantime, treating the problems that can actually be identified and treated is the most productive place to start.

Persistent Concussion Symptoms? The Concussion Solution Can Help

If you're dealing with ongoing symptoms after a concussion, The Concussion Solution provides a structured, comprehensive approach to addressing the systems that commonly contribute to persistent concussion symptoms.

The online program includes guided exercise progression, vestibular strategies, autonomic retraining, visual and cognitive exercises, neck and headache strategies, sleep guidance, and other tools designed to help you work systematically through recovery.

Learn More About The Concussion Solution

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Annie Howard https://www.happybrainpt.com