How to Write About Brain Damage (Accurately!)

It’s not uncommon for a character in a story to become concussed—in fact, when was the last time you read or watched someone get knocked unconscious after being bashed in the back of the skull? It was probably recent, wasn’t it? However, despite that being a popular tactic for writers to quickly incapacitate their characters, it’s not the sort of thing people can realistically brush off as easily as characters tend to do in fiction. Concussions are serious injuries with many consequences, after all. 

Injuries abound in stories of all genres, but head injuries are among the most confusing and challenging to write. When a character takes a blow to the head, their recovery could be anything but simple. Since the brain is responsible for everything the character does and understands, brain damage can impact the way they move, think, speak, behave, and live the rest of their life. Recovery looks different for every person, and some people may never fully recover. Not only that, but the way the injury was sustained and the area of the brain that was affected can have huge impacts on the way the damage manifests. Even if the injury doesn’t seem severe, it could still have lasting consequences.

Naturally, writing about such a complicated topic is not the easiest thing in the world. With that said, it’s not impossible. As long as you take the time to understand the basics, you don’t need to be a neurologist to be able to write about brain damage convincingly. 

What is Brain Damage?

“Brain Damage” is a term used to describe any damage done to the brain for any reason, whether that be permanent or temporary. 

A Character suffering from brain damage will have some kind of impaired brain functioning as a result of the damage, often in the areas of memory, motor control, sleep, emotional control, pattern recognition, learning, and logical thinking. What that specifically looks like, however, is also going to depend on what caused the damage and how severe the damage is.

What Causes Brain Damage?

If you’re like most people, you probably think of Traumatic Brain Injury when you hear the term “brain damage,” but taking a baseball to the skull isn’t the only way a brain can become damaged. 

Traumatic Brain Injury

Traumatic Brain Injury (TBI) is a type of brain damage caused by external trauma to the brain, and it can be mild (such as taking a soccer ball to the face) or severe (such as surviving a high-speed car accident). 

Concussions, also known as Mild Traumatic Brain Injuries (MTBI), are some of the most common and widely understood forms of brain damage. Concussions occur when the brain moves suddenly inside the skull, causing it to stretch, twist, or bash against the inside walls of the skull. This happens when a person’s head moves suddenly—often due to a violent blow or accident. This sounds pretty serious, but most concussions heal perfectly fine on their own with proper rest.

Repeated concussive or subconcussive blows to the head over a period of time can also result in degenerative brain damage. This is referred to as Chronic Traumatic Encephalopathy (CTE), and it is most common in people who play high-intensity sports like football or boxing. 

More severe forms of TBI, on the other hand, can be devastating. TBI encompasses not only severe blunt force trauma but also when something actually breaks through the skull and pierces the brain tissue itself. 


Physical trauma aside, a brain can also become damaged as a result of illness. Some of these illnesses include, but are not limited to:

  • Meningitis
  • Stroke
  • Encephalitis (inflammation of the brain)
  • Brain aneurysm (swelling of a blood vessel in the brain)
  • Brain hemorrhage (also known as “brain bleed”)
  • Brain tumor
  • Hydrocephalus (excess fluid around the brain)
  • And more

In some cases, even the surgeries done to treat these conditions or repair damage done by TBI can result in brain damage as well. 


The brain will also become damaged if there is an insufficient supply of oxygen to support normal brain functioning. If the cells in the brain do not get enough oxygen, they begin to die very quickly. This is referred to as Anoxia (complete lack of oxygen in the brain) and Hypoxia (a partial lack of oxygen to the brain, which is still enough to cause damage).

Anoxia/hypoxia can occur as a result of:

  • Cardiac arrest
  • Low blood pressure as a result of bleeding out (aka “Shock”)
  • Asphyxiation
  • Electric shock
  • Carbon monoxide poisoning
  • Smoke inhalation
  • Seizure
  • Asthma attacks
  • Poison
  • Extremely high altitudes 
  • Nearly drowning
  • And more

How Does Brain Damage Affect Someone?

Brain damage can have devastating consequences for individuals unlucky enough to experience it. The extent to which it’s going to affect someone, however, depends on several different factors, including:

  • How severe the initial damage was
  • What caused the initial damage
  • Which parts of the brain were affected
  • How soon the person received treatment
  • How much therapy the person received during recovery
  • Whether the person had preexisting conditions, particularly psychological or neurological

The only general thing that can be said about brain damage is that the character will suffer from a deficit in some area of functioning that wasn’t there prior to the injury or illness. That is as specific as the description can be without any additional information about the brain damage.

Some of the most common issues a person may experience relate to:

  • Cognition (thinking, memory, and reasoning)
  • Sensory processing (sight, hearing, touch, taste, and smell)
  • Communication and language (expression and understanding)
  • Behavior and mental health (depression, anxiety, personality changes, aggression, acting out, and social inappropriateness)

Specific symptoms are more or less likely to manifest depending on which parts of the brain were damaged. Knowing the different parts of the brain and what they are responsible for can help you make educated decisions regarding which symptoms your characters would have.

The Different Parts of the Brain and Their Functions

Different parts of the brain are responsible for different things, so naturally, the symptoms of brain damage will vary depending on which part of the brain is affected. An injury to the right side of the frontal lobe is not going to be anything like an injury to the back left side of the brain. Knowing which parts of the brain are responsible for different functions can help you understand how your character would be affected by their brain damage—or it can help you decide where they need to be injured in order to have the desired symptoms for your plot.

Disclaimer – I’m not a neurologist, and this is all a lot more complicated than I am making it seem. This is just to give you a quick overview of what areas of functioning would be affected depending on where the injury was sustained. Keep in mind, however, that although many parts of the brain can be attributed to certain functions, these different parts work in tandem to achieve different things. Damage to one part of the brain can have unexpected consequences on other aspects of functioning. 


The cerebrum is the largest part of the brain, and the most often injured. It has two hemispheres, the left and the right, which each have four different lobes. Each lobe is responsible for different kinds of tasks, and each hemisphere has unique functions. 

The left side of the brain controls logical thinking, such as writing, arithmetic, speech, and comprehension, while the right side of the brain controls musical ability, creativity, spatial understanding, and artistic ability. Additionally, each side of the brain controls the opposite side of the body, so the left side of the brain controls the right side of the body, and the right side of the brain controls the left side of the body. An injury sustained on the right side of the brain will affect the left side of the body, and vice versa.

The four different lobes in each hemisphere of the cerebrum are called the frontal lobe, the parietal lobe, the occipital lobe, and the temporal lobe. 

The Frontal Lobe

The frontal lobes, as the name suggests, are the frontmost part of the brain. They are the largest of the four lobes, encompassing the entire front part and most of the top of the brain. As you might expect, most concussions occur in the frontal lobes.

The frontal lobes are responsible for many things, but their primary functions are:

  • Executive functioning (planning, organizing, and executing tasks)
  • Problem-solving
  • Personality
  • Emotions
  • Voluntary movement
  • Speech and writing (specifically the motor functions of these tasks, not language comprehension)
  • Intelligence
  • Concentration
  • Working memory
  • Self-awareness

Because the frontal lobe is responsible for so many different things, damage to the frontal lobe can result in varied symptoms. Damage to the frontal lobes can result in:

  • Personality changes
  • Working memory problems
  • Impulsivity
  • Emotional dysregulation
  • Motor or muscle weakness (particularly in one side of the face or body)
  • Impaired speech
  • Difficulty concentrating
  • Decreased libido
  • Diminished sense of taste or smell
  • Clumsiness
  • Depression
  • Impaired judgment
  • Impaired problem-solving abilities
  • Executive dysfunction 

The Parietal Lobe

The parietal lobes are the part of the brain that sits beneath the crown of your head. This part of the brain primarily deals with perception, so it is a little more specialized than the frontal lobes. 

The parietal lobes are primarily responsible for:

  • Interpreting and understanding language
  • Interpreting sensations (such as pain, temperature, touch, etc)
  • Interpreting signals from the senses (such as sight, smell, hearing, etc)
  • Memory (particularly long-term)
  • Spatial perception

Damage to the parietal lobes can result in:

  • Hypo- or hypersensitivity to stimuli (like pain, touch, flavor, texture, sound, etc)
  • Numbness or tingling sensations
  • Difficulty understanding language 
  • Difficulty communicating
  • Confusion between left and right
  • Difficulty maneuvering around a new (or even a familiar) environment
  • Inability to recognize objects or people
  • Poor hand-eye coordination

The Occipital Lobe

The occipital lobes are located in the very back of the brain, and they have an extremely specialized purpose. Due to its location at the back of the head, it is particularly susceptible to damage. 

The occipital lobes are responsible for interpreting visual cues, including:

  • Color
  • Motion
  • Form
  • Light
  • Etc

Damage to the occipital lobes can result in:

  • Blindness or blind spots
  • Vision distortion
  • Inability to read
  • Inability to recognize colors
  • Simultanagnosia (the inability to see things as part of a whole; ie seeing parts of a face without seeing the whole face)
  • Motion blindness (moving objects may appear as a series of still images in a sequence)
  • Visual hallucinations 

The Temporal Lobe

The temporal lobes are the lowest part of the cerebrum, and sit underneath the parietal lobes. 

The temporal lobes are responsible for:

  • Understanding language 
  • Memory
  • Hearing
  • Processing emotions
  • Learning
  • Remembering verbal information
  • Organizational skills

Damage to the temporal lobes can result in:

  • Inability to understand language (particularly if the damage is on the left side)
  • Impaired auditory processing
  • Difficulty learning and retaining new information
  • Loss of musical or artistic ability
  • Difficulty categorizing objects or ideas
  • Loss of inhibition (particularly in regards to speech)
  • Face-blindness
  • Changes in libido
  • Impaired long-term memory
  • Loss of existing memories
  • Changes in personality (particularly relating to increases in paranoia and rage)

Memory problems are common in individuals who suffer from damage to their temporal lobes. That’s a challenge in itself to convey, so if you want some pointers, make sure you check out How to Write a Character with Amnesia. 

Additionally, the development of anger issues is common in individuals with temporal lobe damage. Take a peek at Writing a Character with Anger Issues if this is something you want to explore for your character. 


The cerebellum is the part of the brain that sits beneath the cerebrum, in the back of the skull. It is primarily understood to be the brain’s motor control center.

The cerebellum is responsible for:

  • Balance and posture (otherwise known as a body’s vestibular sense)
  • Coordination
  • Fine motor control
  • Voluntary movements
  • Motor learning (“muscle memory”)

Damage to the cerebellum can result in:

  • Clumsiness
  • Uneven gait
  • Lack of coordination
  • Inability to judge distance
  • Tremors
  • Abnormal eye movements (such as jittering back and forth or up and down, causing scattered vision)
  • Dizziness (particularly immediately following the injury)
  • Slurred speech
  • Weakened muscles
  • Inability to measure strength being exerted (such as using more or less force than necessary to do something)
  • Inability to perform rapid alternating movements


The brainstem is the part of the brain that connects to the spinal cord. Brain damage occurring in the brainstem is relatively rare, but among the most alarming and severe kinds. 

The brainstem is responsible for regulating automatic processes that keep the body alive, such as:

  • Breathing
  • Blood pressure
  • Swallowing
  • Body temperature
  • Sleep/wake cycles
  • Taste

Damage to the brainstem can result in:

  • Dizziness
  • Abnormal sleep patterns or insomnia
  • Balance issues
  • Persistent nausea
  • Difficulty eating or drinking
  • Slurred speech
  • Abnormal breathing patterns or difficulty breathing
  • Impaired vision
  • Altered heart rate
  • Paralysis
  • Coma

A person with brainstem damage may depend on life support technology to keep them alive, either only during their initial recovery or for the rest of their life. 

Writing About Comas

When a person experiences severe trauma to their brainstem (and other parts of their brain, in some cases), they may end up slipping into a coma. A coma is a prolonged period of unconsciousness from which a person cannot wake up, due to their brain’s inability to function normally.

In almost all cases, this is temporary, and the person wakes up again within a matter of days or weeks. Only rarely does a coma last more than a month, regardless of whether it is medically induced or the direct result of brain trauma. I cover this topic at length in another article: How to Write a Character in a Coma. Check that out for a lengthy explanation of the different kinds of comas, the length of time a character could be in a coma, and what the process of waking up from a coma looks like.

Is Brain Damage Reversible? 

The answer to whether brain damage is reversible or not is a little complicated. Once brain cells die, they are simply dead. They cannot heal or be replaced. However, a character can still regain many (or all) of the skills they had prior to the injury—even if that injury was fairly severe. 

Brains are remarkably adaptive. Often, when an injury occurs, the brain finds ways to rewire neurons around the injury. These new neural pathways can allow someone to relearn functions they lost when they first experienced their injury, such as social appropriateness, the ability to read, or the ability to perform specific motor tasks. This doesn’t mean they will make a full recovery, but rather, their brain simply learns a new way to achieve a similar end. 

With that said, this retraining of the brain is not something that happens automatically. This is the result of specific therapies and lifestyle changes guided by a team of medical professionals. Without appropriate treatment, the character’s ability to recover will be severely inhibited. 

For a really cool story about someone who recovered from a metal rod going straight through his brain, check out the story of Phineas Gage on Wikipedia. Read at your own risk, though—some of the descriptions are pretty graphic. 

Writing About Treatment for Brain Damage

If you’re going to give one of your characters brain damage in your story, then you’re going to need a basic understanding of what treatment for brain damage looks like. 

Initial Care

When a character sustains an injury to the brain, the very first step in their treatment would be stabilization. If the character is bleeding out, then that would be addressed first—injuries are bandaged, fluids are supplied via IV, and blood pressure is stabilized. The most important thing is to ensure the brain maintains a stable blood flow, since a lack of blood results in not enough oxygen getting to the brain’s cells, which causes more damage. 

Next, the extent of the character’s injuries has to be determined. Doctors will examine them for signs of whiplash, bruising, broken bones, and more. In cases where something has broken through the skull, bone fragments often get lodged in the brain and must be surgically removed.

Surgery is sometimes a necessary step in the character’s initial recovery. If there is uncontrollable swelling in the brain, areas of the skull, face, or scalp that need to be reconstructed, dead brain tissue that needs to be removed, or any number of other complications, surgery is the only option. 

The Early Stages of Recovery

Treatment in the days or weeks following the injury varies greatly depending on the extent and area of the damage. For concussions, as long as there are no obvious signs of complications, recovery mostly constitutes resting at home for a few weeks and gradually introducing physical activity when the character begins to feel better.

For more severe brain damage, characters would be kept in the hospital to be monitored 24/7, to ensure they continue to breathe and eat, but also to ensure someone is on hand to respond to complications like hemorrhaging or seizures. 

At this stage, depending on if the character is conscious or not, doctors would quiz them on various things to determine if they are delirious or suffering from any damage to their intellect, memory, or critical thinking skills. 

If the character is unconscious (either momentarily or comatose), then their care at this stage would mostly involve keeping them stable and attending to their vitals and everyday needs. 


Once the character is conscious and physically recovered, their treatment would shift. They would no longer require constant attention from doctors to keep them alive. Even if they were left physically scarred from the accident, or they require certain medical technology to stay alive, self-managed care at home is often an option. 

At this stage, the character would likely require some combination of physical therapy, speech therapy, cognitive therapy, occupational therapy, psychotherapy, and social support depending on their individual needs. The process of recovering could take several years, and the person may never get back to exactly how they were before the injury.

Can Brain Damage Cause a Personality Change?

Brain damage can (and often does) result in changes to a person’s personality, but it’s not really as simple as you might think. It’s important to keep in mind here that correlation is not the same as causation. 

When a person is in a serious accident that results in brain damage, it is not just physical trauma they experience, but emotional trauma as well. Serious accidents are scary. Medical problems are terrifying. Gaps in memory and periods of unconsciousness, pain, and confusion can be extremely traumatizing. 

A character suffering from brain damage likely also has PTSD from the situation that gave them the brain damage, and as a result, also likely develops some combination of depression, anxiety, anger issues, dissociative disorders, paranoia, and more. These psychological problems could be the root of most personality changes following a traumatic brain injury. That behavior shouldn’t be misattributed to brain damage when it is more appropriately attributed to psychological stress.

With that said, in some cases, severe damage to the brain (particularly in the frontal lobes) can directly result in changes to a person’s personality. A person may experience mood swings, lack of appropriate reactions to situations, loss of empathy, and a lack of awareness of their own deficits. They may behave as if they have no inhibitions, and act inappropriately in social situations. However, brain damage does not vastly alter who a person fundamentally is. Rather, personality changes are most often exaggerations of the person’s previous personality traits. 

The Worst-Case Scenario

As with many injuries, no one is guaranteed a chance to recover. Sometimes, brain injuries are too severe to recover from.

Characters with brain damage can die as a result of:

  • Brain hemorrhage 
  • Seizure
  • Infection
  • Brain death
  • Stroke
  • Blood clots
  • And more

If killing your character was always your goal, you could find some useful information in A Guide to Killing Your Characters.

As always, remember to be compassionate and considerate when portraying conditions like brain damage in your fiction. 

I know this topic is challenging, but I believe in you! Keep creating, writers!