How long does a concussion take to heal?

Most people recover within two to four weeks, with symptoms improving steadily over the first days. Anything still going at a month deserves a neurological evaluation.

What are the symptoms of a minor concussion?

The same kinds of symptoms as any concussion, usually milder: a headache, feeling foggy or slowed, mild dizziness or nausea, sensitivity to light or noise, and feeling more tired or irritable than usual. A minor concussion still needs a short period of relative rest and a graded return, and it still counts toward the total.

How many concussions is dangerous?

There is no set number. The concern is the pattern: concussions that come from smaller hits, recoveries that take longer each time, or symptoms that never fully cleared before the next injury. Any of those is a reason to see a neurologist and to reconsider contact sport.

Can post-concussion syndrome show up years later?

Symptoms that begin years after a concussion, with a full recovery in between, are unlikely to be caused by that injury and are more often due to something new, such as migraine, a sleep disorder, or depression. Symptoms that never fully resolved can persist for years, usually because a treatable secondary problem was never addressed.

Do I need a CT scan or MRI after a concussion?

Usually not. Concussions do not show on either scan. Imaging is used in the emergency setting to rule out bleeding or a fracture when warning signs are present, and later only if symptoms are unusual or not improving.

Can you drive or fly after a concussion?

Driving waits until reaction time, attention, and vision are back to normal, usually within a couple of weeks. Pilots generally need a neurological evaluation and a symptom-free interval before the FAA restores a medical certificate, and we provide both that and DMV evaluations.

Concussion Symptoms, Recovery and Post-Concussive Syndrome

A young adult in a hoodie beneath a calm brain illustration.

You hit your head, and something is not right. This page covers which symptoms mean go to an emergency department now, what normal recovery looks like, what to do when it drags past a month, and what repeated concussions do and do not mean for the long term.

What a concussion is

A concussion is a mild traumatic brain injury caused by a blow or jolt to the head, or a hit to the body forceful enough to move the brain rapidly inside the skull. That movement disrupts the chemistry of brain cells and stretches their connections.

It is an injury to how the brain works, not to its structure. That is why a concussion does not appear on a CT or MRI, and why a normal scan never means the concussion was not real. Research scans such as diffusion tensor imaging can pick up changes when groups of injured people are compared with groups who are not, but they are research tools and are not validated for diagnosing an individual. A CT in the emergency department answers one question, whether there is bleeding or a fracture. Being told "your scan is clear" means that question was answered, not that you are fine.

Visual guide

Symptoms beyond the initial injury

Symptoms: Headache and difficulty concentrating can follow a concussion.
Other effects: Balance and sleep may also change.
Recovery: Persistent symptoms are evaluated for specific treatable causes.

A concussion can affect thinking, balance, sleep, and how the head feels.

Concussion symptoms, including a minor concussion

Symptoms may not start immediately. Someone who seemed fine at the time can feel much worse hours later. A minor concussion has the same kinds of symptoms as a more severe one, usually milder and shorter, and it still needs the same care in the first days.

Head: headache or pressure, sensitivity to light or noise
Balance: dizziness or unsteadiness, nausea
Thinking: feeling in a fog, slowed processing, memory gaps around the injury
Energy and mood: feeling sluggish, irritability, tearfulness
Sleep: sleeping much more or much less than usual

Diagnosis is clinical: an account of the injury, a neurological examination covering balance and eye movements, and a check of memory, attention, and processing speed, briefly in the office or with neuropsychological testing when symptoms persist.

When a head injury is an emergency

Most concussions are not dangerous, but a small number of head injuries cause bleeding or swelling, and those declare themselves through specific signs. Go to an emergency department or call 911 for any of the following after a head injury.

Warning sign	Why it matters
A headache that keeps getting worse	The classic sign of a bleed expanding inside the skull
Repeated vomiting	Rising pressure rather than simple nausea
Difficulty waking, or unconsciousness beyond a minute or two	A structural injury, not a concussion
Increasing confusion or agitation	Brain function deteriorating rather than settling
A seizure	Needs imaging and observation the same day
Weakness, numbness, slurred speech, unequal pupils	Focal damage that imaging has to rule out

Recovery, step by step

The old advice was strict rest in a dark room until symptoms cleared. We no longer recommend it, because prolonged rest makes recovery slower rather than faster. The current approach is a short period of relative rest, then a graded return with symptoms as the guide.

The first 24 to 48 hours
Sleep normally at night. Limit screens and demanding mental work, and avoid any risk of a second impact. This is rest relative to your usual day, not a blackout room.
Return to learn, in four steps
Daily activities at home, then school-type work at home, then part-time school, then full-time school. This progression comes before the return to sport, and most people manage a partial day within the first week. We write the accommodations letter when one is needed.
Return to sport, in six steps
One, symptom-limited daily activity. Two, light and then moderate aerobic exercise. Three, individual sport-specific exercise with no risk of head impact. Four, non-contact training drills. Five, full contact practice. Six, return to sport. Each step takes a minimum of 24 hours, so the full progression takes at least a week. Steps one to three can be done with mild symptoms. A clinician must clear you before step four, and a written clearance is advised before an unrestricted return.
How much of a symptom bump is acceptable
A mild, brief increase is fine: no more than about 2 points on a 0 to 10 scale, lasting under an hour. Beyond that, stop, and repeat the same step the next day.
Follow-up
If symptoms plateau or worsen at any stage, that is the point to be reassessed rather than push through.

Do not return to contact sport before you are cleared

A second head impact before the first concussion has healed can cause a far more serious injury than the original one. Complete the graded return and be cleared by a clinician before going back to contact or collision sport.

A resting chair, person taking an easy walk, and a simple desk with a closed laptop. — Recovery balances early relative rest with a symptom-guided return to everyday activity.

When symptoms last: post-concussive syndrome

Most concussion symptoms resolve within a few weeks. When headache, dizziness, fatigue, poor concentration, disturbed sleep, or mood changes persist for months, that is post-concussive syndrome, now often called persisting symptoms after concussion. It is more likely after repeated concussions, with a history of migraine, anxiety, or depression, and when the early recovery involved prolonged strict rest.

The label is less important than what sits behind it. Persisting symptoms are rarely a sign of ongoing brain damage. They are usually driven by several secondary problems the injury set off, each of which can be found and treated: a migraine pattern, an inner-ear injury, neck strain, disrupted sleep, and the anxiety that builds when recovery stalls. That is why it is treated symptom by symptom rather than with a single prescription.

Persistent symptom	What actually helps
Headache	Post-traumatic headache behaves like migraine and is treated the same way. See our headache service
Dizziness or unsteadiness	Vestibular physical therapy, the most effective treatment we have
Fog, memory, concentration	Neuropsychological testing to measure what is affected, then cognitive rehabilitation
Fatigue and disturbed sleep	A fixed sleep schedule first, short-term sleep medication only if needed
Anxiety or low mood	Cognitive-behavioral therapy, which also reduces the fear of activity
Neck pain and neck-related headache	Physical therapy, often overlooked and frequently the missing piece

Two things worth knowing. Frequent use of over-the-counter pain relievers is a common reason post-traumatic headaches will not settle, so we ask about it at every visit. And transcranial magnetic stimulation and neurofeedback are marketed for post-concussive symptoms on evidence that is still preliminary, so we neither offer nor recommend them ahead of the treatments above.

We provide the testing and the medical management. We refer to the cognitive rehabilitation specialists, vestibular therapists, and therapists who provide the rest.

Symptoms years after a concussion

People sometimes arrive years after a head injury asking whether their headaches, fog, or mood are still "from the concussion". Sometimes they are, particularly a migraine pattern the injury switched on that was never treated as migraine. Often something else has developed since, such as a sleep disorder, depression, or a thyroid problem, and the injury is being blamed by default. Sorting that out is what a neurologist adds at that stage: a fresh look at the whole picture rather than an assumption either way.

Multiple concussions, long-term effects, and CTE

Each concussion makes the next one a little easier to get and a little slower to recover from, and the risk of persisting symptoms rises with the count. There is no fixed number that is dangerous. What matters more is whether each injury was allowed to heal before the next, how long the recoveries took, and whether the injuries are becoming more frequent or more severe. A pattern of longer recoveries after each concussion is the point at which a serious conversation about continuing a contact sport is warranted.

Chronic traumatic encephalopathy (CTE) is the long-term concern most people have read about. The honest state of the evidence: CTE is a degenerative brain disease linked to years of repeated head impacts, including the many sub-concussive hits of contact sports, and it can currently be confirmed only by examining the brain after death. It has not been established that a few concussions, without that kind of repetitive exposure, cause it. Memory, mood, and thinking changes years after a couple of concussions have far more common and more treatable explanations, and those are evaluated first.

A clinical syndrome linked to the same exposure, traumatic encephalopathy syndrome, can be described in a living person using 2021 research criteria. Those criteria are for research, and a diagnosis of traumatic encephalopathy syndrome is not the same as confirming CTE in the brain.

When to see a neurologist

Most concussions are handled well by a primary care or sports medicine clinician. See a neurologist when symptoms last beyond three or four weeks, when headache or dizziness is the main problem, when you have had more than one concussion, when symptoms years later are being attributed to an old injury, or when you need formal documentation for work, school, the DMV, or the FAA.

A visit with Dr. Achillefs Ntranos, MD is 60 minutes, and you leave with a written plan. We also provide DMV driver evaluations and FAA neurological evaluations after a head injury. You can request a visit in Beverly Hills or Los Angeles, or by video anywhere in California.

Concussion and Post-Concussive Syndrome: Symptoms, Recovery, and When to See a Neurologist