Quick answer
Post-concussion syndrome (PCS) is a group of physical, thinking, emotional and sleep symptoms that last longer than expected after a concussion or other traumatic brain injury.[1][2] NINDS describes it as symptoms that last for weeks or longer.[2] A clinical review on NCBI Bookshelf estimates that about 15% of people with a mild TBI develop PCS, and says the outlook is generally good, with most people improving within three months.[1]
What PCS is
Most concussion symptoms fade within days to weeks. The CDC states that most people with a mild TBI or concussion feel better within a couple of weeks.[3] When symptoms continue beyond that, clinicians may use the term post-concussion syndrome (also called post-concussive syndrome or persistent post-concussive symptoms).
The CDC notes that if one or more symptoms last for months after the injury, a healthcare provider may talk about post-concussive syndrome.[4] According to the StatPearls review, PCS is seen most often after a mild TBI, but it can also follow moderate and severe TBI.[1]
How it’s defined
There is no single agreed definition. The StatPearls review describes two sets of clinical criteria that can give different results even in the same group of patients:[1]
- DSM-IV: problems with attention or memory plus at least three other symptoms (such as fatigue, sleep disturbance, headache, dizziness, irritability, mood changes, or apathy and personality changes) lasting three months or longer.[1]
- ICD-10: similar symptoms lasting longer than three weeks, a broader definition that includes more patients.[1]
The same review notes that symptoms lasting past three months are sometimes called persistent PCS.[1]
Symptoms
The StatPearls review lists headache, fatigue, vision changes, balance problems, confusion, dizziness, insomnia, mood and other neuropsychiatric symptoms, and trouble concentrating.[1]
Physical
- Headache
- Dizziness and balance problems
- Fatigue
- Vision changes
Thinking
- Trouble concentrating
- Memory problems
- Confusion
Emotional
- Irritability
- Depression or anxiety
- Personality changes
Sleep
- Insomnia
- Sleep disturbance
NINDS notes that emotional symptoms such as frustration and irritability tend to develop during recovery rather than right after the injury.[2]
How common it is
Estimates vary widely because definitions differ. The StatPearls review reports that:[1]
- About 90% of concussion symptoms are temporary, typically resolving within 10 to 14 days.
- About 15% of people with a mild TBI develop PCS, though limited diagnostic tools mean this may be an underestimate.
- Published studies report a much wider range, from 30% to 80% of people with mild to moderate TBI having some PCS symptoms.
- A minority, reported at 10% to 15%, have symptoms lasting more than a year, though the authors caution that these figures may be overestimated.
Risk factors
The StatPearls review lists factors associated with a higher risk of lasting symptoms:[1]
- Having had more than one TBI
- A “complicated” mild TBI, meaning concussion symptoms plus CT findings such as a hematoma, bleeding or a fracture
- Female sex
- Older age
- A history of psychiatric conditions or chronic pain
- More severe symptoms at first presentation, or repeated head trauma, which have been linked to symptoms lasting more than one month
The review also notes that studies have not consistently shown that the severity of the original injury predicts who develops PCS.[1] The CDC notes that recovery may be slower among older adults, young children and people who have had a concussion before.[4]
Why symptoms persist
The exact cause is not fully understood. The StatPearls review describes a combination of metabolic, physiological and microscopic structural injury to the brain.[1] It describes research linking PCS to disruption of the autonomic nervous system, which regulates blood flow to the brain, blood pressure and heart rate, and which may explain dizziness, headache and exercise intolerance.[1] The review also notes that psychological factors such as depression, anxiety and post-traumatic stress can produce overlapping symptoms, and that both physical and psychological factors may contribute.[1]
Treatment
There is no single treatment for PCS. According to the StatPearls review, treatment is tailored to each person’s symptoms, and education and reassurance are a major part of care.[1] Approaches described in the medical literature include:
- Graded physical activity: the 2023 international consensus statement on sport concussion found that prescribed aerobic exercise below the symptom threshold, started within 2 to 10 days of injury, reduces the chance of symptoms lasting longer than one month.[5]
- Vestibular, vision and neck therapy: for lasting dizziness, balance or visual symptoms, the StatPearls review describes vestibular rehabilitation, vision therapy and cervical physical therapy.[1] See Vestibular therapy.
- Headache treatment: the review lists several medications and procedures used for post-traumatic headache.[1]
- Cognitive rehabilitation: for ongoing problems with attention, memory or planning. See Cognitive rehabilitation.
- Treating related conditions: the review notes that treating related conditions such as PTSD, other psychiatric conditions, chronic headaches and pain syndromes helps patients recover.[1]
The review also notes that extended bed rest can lead to worse outcomes.[1]
Outlook
The StatPearls review describes the prognosis for PCS as generally good.[1] Symptoms are usually worst in the first week and improve over the following month, and the vast majority of people recover by three months.[1] A small number continue to have disabling symptoms after several months or a year.[1] NINDS notes that recovery from a second or third concussion is generally slower than from a first.[2]
If someone else caused the injury
Lasting symptoms after a crash, fall or other preventable accident can affect work, school and daily life. Medical records that document symptoms over time can matter in insurance and injury claims. See Proving a mild TBI.
Frequently asked questions
How long does post-concussion syndrome last?
It varies. The StatPearls review reports that most people improve within three months, while a small minority have symptoms for a year or longer.[1]
Can PCS happen after a “mild” concussion?
Yes. PCS is seen most often after mild TBI, and studies have not consistently linked the severity of the original injury to the risk of PCS.[1]
Does a normal CT scan rule out PCS?
No. NINDS notes that standard imaging and other tests can’t always detect damage from mild, concussive injuries.[2]
This page provides general information from the sources listed below. It is not medical advice and is not a substitute for evaluation by a qualified healthcare provider. In an emergency, call 911.
Sources
- Permenter CM, Fernández-de Thomas RJ, Sherman AL. “Postconcussive Syndrome.” StatPearls, NCBI Bookshelf, updated August 28, 2023. https://www.ncbi.nlm.nih.gov/books/NBK534786/
- National Institute of Neurological Disorders and Stroke. “Traumatic Brain Injury (TBI).” https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi
- Centers for Disease Control and Prevention. “Symptoms of Mild TBI and Concussion.” https://www.cdc.gov/traumatic-brain-injury/signs-symptoms/index.html
- Centers for Disease Control and Prevention. “What to Do After a Mild TBI or Concussion.” https://www.cdc.gov/traumatic-brain-injury/response/index.html
- Patricios JS, et al. “Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport–Amsterdam, October 2022.” British Journal of Sports Medicine, 2023. https://bjsm.bmj.com/content/57/11/695
Sources last checked: October 11, 2026
