Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) results from a sudden blow or jolt to the head. Severity ranges from mild concussion to severe injury requiring intensive care. Most TBIs are mild, but proper recovery is important to reduce lingering effects.

Table of Contents

Quick Facts

  • ICD-10: S06
  • Severity scale: Glasgow Coma Scale
  • Common cause: Falls, motor vehicle, sports
  • Mild TBI = concussion: Yes

When to Call 911

Call 911 or go to the emergency department for any head injury with:
  • Loss of consciousness (even briefly)
  • Repeated vomiting
  • Severe or worsening headache
  • Confusion, slurred speech, unusual behavior
  • Weakness, numbness, or coordination problems
  • One pupil larger than the other
  • Seizure
  • Clear fluid or blood draining from nose or ears
  • Injury during sport with any 'red flag' symptoms — no return to play that day

Overview

A TBI occurs when an external force damages the brain. Mechanisms include falls, motor vehicle crashes, sports injuries, assaults, and blast exposures. TBI severity is classified using the Glasgow Coma Scale, duration of loss of consciousness, and post-traumatic amnesia.

Types and Severity

  • Mild TBI (concussion) — GCS 13–15; usually no abnormal brain imaging; recovery typically within days to weeks.
  • Moderate TBI — GCS 9–12; may have abnormal imaging; longer recovery.
  • Severe TBI — GCS 3–8; significant injury requiring intensive care; longer-term effects common.

Symptoms

Mild (concussion)

  • Headache
  • Dizziness, balance problems
  • Nausea
  • Confusion, feeling 'foggy'
  • Sensitivity to light or noise
  • Fatigue, sleep changes
  • Memory or concentration difficulty
  • Irritability or mood changes

Moderate to severe

  • Persistent headache that worsens
  • Repeated vomiting or nausea
  • Convulsions or seizures
  • Inability to wake
  • Dilated pupil(s)
  • Slurred speech
  • Weakness or numbness in extremities

Diagnosis

  • Neurologic exam and Glasgow Coma Scale
  • CT scan — first imaging in moderate-severe injury or red flags
  • MRI — for prolonged symptoms or to detect subtle injury
  • Cognitive and balance testing for concussion management

Treatment

Mild TBI / concussion

  • Physical and cognitive rest initially (1–2 days)
  • Gradual return to activity guided by symptom tolerance
  • Avoid alcohol and risk of re-injury during recovery
  • Treat headache, sleep, and mood symptoms
  • Vestibular and cervical therapy if persistent symptoms

Moderate-severe TBI

  • Emergency stabilization and intracranial pressure management
  • Neurosurgical intervention for bleeding, swelling, or skull fractures
  • ICU monitoring
  • Long-term rehabilitation (PT, OT, speech, cognitive)

Recovery

Most concussions resolve within 2–4 weeks. About 10–20% of patients have symptoms lasting longer (post-concussion syndrome). Moderate to severe TBI may require months to years of rehabilitation, and long-term cognitive, emotional, or physical changes are common.

Prevention

  • Use seat belts and child safety seats
  • Wear helmets for biking, motorcycling, skiing, and contact sports
  • Prevent falls — especially in older adults and young children (home safety, balance training)
  • Avoid driving under the influence
  • Follow concussion protocols in sports

When to See a Doctor

Anyone with a moderate or severe head injury should be evaluated immediately. For mild injuries, see a doctor if symptoms persist beyond 1–2 weeks, worsen, or new neurologic symptoms develop.

Related Conditions

Concussion

Most common form of mild TBI

 Headache

Common after TBI

 Confusion

Acute or chronic TBI symptom

 Memory Loss

Often follows TBI

Frequently Asked Questions

How is a concussion different from a TBI?

A concussion is a mild traumatic brain injury. All concussions are TBIs, but not all TBIs are concussions — the term TBI also includes more severe injuries.

When can I return to sports after a concussion?

Return-to-play follows a graduated step-wise protocol guided by symptoms. Most athletes can return after about a week of progression, but no one should return on the day of injury or while still having symptoms.

Is it dangerous to sleep after a head injury?

Sleep itself isn't harmful and is part of recovery. The historic advice to keep someone awake came from the inability to recognize worsening symptoms. Modern guidance: if a doctor cleared you, sleep is fine; watch for worsening symptoms when awake.

Can repeat concussions cause long-term damage?

Repeated concussions, especially in close succession, increase risk of prolonged symptoms and potentially chronic traumatic encephalopathy (CTE). Strict return-to-play protocols reduce this risk.

Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you are experiencing a medical emergency, call your local emergency number immediately.

References

  • Centers for Disease Control and Prevention. Traumatic Brain Injury & Concussion.
  • Brain Injury Association of America. About Brain Injury.