A traumatic brain injury (TBI) is a brain injury caused by a sudden blow, bump, or jolt to the head that disrupts normal brain function. TBIs range from mild — a brief concussion — to severe, involving prolonged unconsciousness, permanent disability, or death. Falls and car accidents are the most common causes.
These injuries are far more serious and far more common than most people expect. The CDC reports that TBIs contribute to about 190 deaths per day in the United States. Millions more are treated in emergency rooms or go entirely undiagnosed.
How Is a TBI Classified? Mild, Moderate, and Severe
Doctors classify traumatic brain injuries into three grades based on how severely brain function was disrupted.
Mild TBI (Concussion)
Mild TBI — commonly called a concussion — is the most frequent type. Despite the word "mild," these injuries can cause lasting problems. A mild TBI involves:
- Loss of consciousness lasting 30 minutes or less, or no loss of consciousness at all
- Confusion or disorientation lasting less than 24 hours
- A Glasgow Coma Scale (GCS) score of 13–15 (a clinical scale that measures responsiveness)
- Post-traumatic amnesia lasting less than 24 hours
Symptoms often include headache, confusion, dizziness, and sensitivity to light or noise. Many people with mild TBI never lose consciousness and don't realize they've been injured at all.
Moderate TBI
Moderate TBI is more serious. It involves:
- Loss of consciousness lasting between 30 minutes and 24 hours
- Confusion or altered mental state lasting up to 24 hours
- A GCS score of 9–12
- Post-traumatic amnesia lasting 1–7 days
People with moderate TBI typically need hospitalization and weeks to months of rehabilitation.
Severe TBI
Severe TBI is the most serious form. It involves:
- Loss of consciousness lasting more than 24 hours, or coma
- A GCS score of 8 or below
- Post-traumatic amnesia lasting more than 7 days
Severe TBI can cause permanent physical, cognitive, and behavioral changes. Some patients never fully recover.
What Causes a Traumatic Brain Injury?
Any event that sends sudden force through the head or body can cause a TBI. The most common causes:
Falls — Falls are the leading cause of TBI overall, especially among adults 65 and older and children under 4. A fall from a ladder, down stairs, or on a slippery surface can produce a TBI even without a visible head wound.
Motor vehicle accidents — Car, truck, motorcycle, and bicycle crashes are among the most common causes of TBI hospitalizations and deaths, especially for people between ages 15 and 44.
Being struck by or against an object — This includes being hit by falling objects at construction sites, being thrown against a surface in a crash, or being struck during an assault.
Assault and violence — Gunshot wounds to the head and physical assaults account for a significant share of severe TBIs, particularly in urban areas.
Sports and recreational injuries — Contact sports like football, boxing, and hockey carry TBI risk, as do cycling and skiing — especially with repeated lower-level impacts over time.
Workplace accidents — Construction workers and factory workers face elevated TBI risk from falls, falling objects, and machinery accidents.
What Are the Symptoms of a Traumatic Brain Injury?
TBI symptoms depend on the severity of the injury. Symptoms can appear hours or even days after the initial impact — don't dismiss a head injury because you feel fine right away.
Symptoms of Mild TBI
- Headache (the most common symptom)
- Confusion or feeling "foggy"
- Brief loss of consciousness — or none at all
- Dizziness or loss of balance
- Nausea or vomiting
- Blurred vision
- Sensitivity to light and noise
- Difficulty concentrating or remembering new information
- Sleep disturbances — sleeping more than usual or being unable to sleep
- Mood changes, irritability, or depression
Symptoms of Moderate to Severe TBI
- Headache that gets worse and won't go away
- Repeated vomiting
- Seizures or convulsions
- Loss of consciousness lasting more than a few minutes
- Extreme confusion or agitation
- Slurred speech
- Weakness or numbness in fingers and toes
- One or both pupils unusually large (dilated)
- Inability to be awakened from sleep
If someone shows signs of moderate or severe TBI after a head injury, call 911 immediately. These are medical emergencies.
How Is TBI Diagnosed?
Diagnosing a TBI involves several tools:
Neurological exam and GCS scoring — In the emergency room, doctors assess responsiveness using the Glasgow Coma Scale. They also check reflexes, eye movement, pupil reaction, and motor function.
CT scan — A CT scan is the standard first imaging tool after a suspected TBI. It can detect bleeding, bruising, or swelling in the brain.
MRI — MRI provides more detailed images. Doctors use it in follow-up care when CT results are unclear or symptoms persist.
Neuropsychological testing — For ongoing cognitive symptoms, testing assesses memory, attention, language, and problem-solving. This matters especially for mild TBI — CT and MRI scans can appear normal even when a patient has real, measurable cognitive problems.
A normal scan does not mean a normal brain. Mild TBI is partly a clinical diagnosis based on symptoms and the mechanism of injury, not just imaging.
Long-Term Effects of a TBI
Even a "mild" TBI can have lasting consequences. Recovery depends on the severity of the initial injury, the person's age and health, and how quickly they received treatment.
After Mild TBI
Most people recover fully within a few weeks. Some develop post-concussion syndrome — a cluster of symptoms (headache, dizziness, cognitive fog, mood changes) that can last months or longer. Risk factors include a prior concussion, anxiety or depression, and returning to activity too soon.
Second-impact syndrome is a rare but dangerous risk: a second concussion before the first has healed can trigger rapid, severe brain swelling. This is why doctors restrict athletes from returning to play before full recovery.
After Moderate to Severe TBI
Long-term consequences can include:
- Cognitive effects: Problems with memory, attention, processing speed, and decision-making
- Physical effects: Chronic headaches, dizziness, fatigue, seizures, and motor impairments
- Emotional and behavioral effects: Depression, anxiety, personality changes, impulsivity, and social difficulties
- Sensory effects: Ringing in the ears, vision problems, loss of smell or taste
- Long-term neurological risk: Research shows TBI survivors have elevated rates of Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions
Severe TBI may result in permanent disability or a vegetative state. Even with extensive rehabilitation, some patients do not regain independent function.
When a TBI Happens Because of Someone Else's Actions
Many TBIs in New York result from accidents caused by another person, business, or property owner — car crashes, falls at a poorly maintained property, construction site accidents, or being struck as a pedestrian. If a TBI resulted from someone else's negligence, the injured person may have legal options.
For information about what to do when a brain injury results from an accident, visit our page on Queens brain injury lawyers.
Frequently Asked Questions About TBI
What is the difference between a concussion and a TBI?
A concussion is a type of traumatic brain injury — specifically, the mildest form. All concussions are TBIs, but not all TBIs are concussions. The term "TBI" covers moderate and severe injuries too, with longer unconsciousness, greater brain damage, and a higher risk of permanent effects. Clinically, "concussion" and "mild TBI" are often used interchangeably.
Can you have a TBI without losing consciousness?
Yes. Loss of consciousness is not required for a TBI diagnosis. Many mild TBIs involve only brief confusion or "seeing stars" rather than blacking out. Someone who hits their head and feels dazed for a moment may have a TBI even without losing consciousness.
How long does a TBI take to heal?
Recovery depends on severity. Most mild TBI symptoms resolve within days to a few weeks. Some people develop post-concussion syndrome, with symptoms lasting months. Moderate TBI recovery typically takes weeks to months. Severe TBI can involve years of rehabilitation, and some effects may be permanent.
Is TBI a disability?
Severe TBI can cause permanent disability affecting physical, cognitive, and behavioral function. Moderate TBI can also leave lasting impairments. Mild TBI is generally not permanently disabling when managed properly, though post-concussion syndrome can temporarily affect a person's ability to work or care for themselves.
What should I do immediately after a suspected head injury?
Get medical attention right away, even if symptoms seem minor. Don't drive yourself. If someone loses consciousness, has a seizure, becomes more confused, or develops a worsening headache, call 911. For milder symptoms, go to an emergency room or urgent care. Don't return to physical activity or mentally demanding work until a doctor clears you.
Sources & Official Resources
Federal Health Agencies
- CDC — Traumatic Brain Injury & Concussion: Facts and Statistics
- CDC — TBI Data
- NIH / NINDS — Traumatic Brain Injury (TBI)
New York State Resources 4. New York State Department of Health — Traumatic Brain Injury Program
Sports & Concussion Safety 5. CDC — Heads Up: Concussion in Youth Sports
Contact The Orlow Firm
If you or a family member suffered a traumatic brain injury in an accident that was not your fault, The Orlow Firm has represented injured New Yorkers for over 40 years. We handle personal injury cases on a contingency basis — no fee unless we win.
Call (646) 647-3398 for a free consultation. Se Habla Español.
