Concussion symptoms include headache, dizziness, confusion, nausea, sensitivity to light or noise, and memory problems. Some appear right away; others surface hours or days later. Emergency warning signs — seizures, a worsening headache, unequal pupils, repeated vomiting, or loss of consciousness — require a 911 call or ER visit. Most concussions clear up within a couple of weeks with proper rest.
A concussion is a traumatic brain injury caused by a bump, blow, or jolt to the head — or by a hit to the body that makes the head snap rapidly back and forth. That sudden movement can bounce the brain around inside the skull, triggering chemical changes in brain cells and sometimes damaging them. The CDC classifies concussion as a "mild" TBI, but that label can be misleading. A concussion is a real brain injury, and its effects can be serious.
One of the most dangerous things about concussions is that symptoms do not always show up right away. People often walk away from car crashes, falls, and workplace accidents feeling fine, only to develop significant symptoms hours or days later. Knowing every category of concussion symptom — and knowing which ones need emergency care — can matter a great deal for your recovery.
The Four Main Categories of Concussion Symptoms
The CDC organizes concussion symptoms into four groups. You do not need symptoms in all four. Even one or two after a head impact is reason enough to stop what you are doing and see a doctor.
Thinking and Memory
- Difficulty thinking clearly
- Feeling slowed down or mentally foggy
- Trouble concentrating
- Problems remembering new information
This category is often the most disorienting. Someone may feel like they are functioning normally while people around them notice they are answering questions slowly or repeating themselves.
Physical Concussion Symptoms
- Headache or a feeling of pressure in the head
- Nausea or vomiting
- Balance problems or dizziness
- Blurry or double vision
- Sensitivity to light or noise
- Fatigue or unusually low energy
The headache from a concussion is usually a dull, throbbing pressure — not a sharp stabbing pain. It may come with a sense of fullness or tightness in the head. Light and noise sensitivity can make it hard to sit in a normal room or look at a phone screen.
Emotional and Mood Changes
- Irritability or a shorter fuse than normal
- Feeling sad or depressed without a clear reason
- Being more emotional than usual
- Nervousness or anxiety
Mood changes after a head injury are often written off as stress. They are real symptoms of brain injury and deserve attention.
Sleep Disturbances
- Sleeping more than usual
- Sleeping less than usual
- Trouble falling asleep despite feeling exhausted
Sleep problems are common after a concussion and slow recovery. The brain needs sleep to heal — which creates a difficult cycle when sleep itself becomes disrupted.
Delayed Concussion Symptoms: What to Watch for After the Injury
Many accident victims are told at the scene that they are fine — and they feel that way at the time. Adrenaline and the shock of the event can hide symptoms in the immediate aftermath. This is why it is important to watch for concussion symptoms for at least 48 to 72 hours after any head impact.
Delayed concussion symptoms can surface anywhere from 24 to 72 hours after an injury. In some cases, signs take up to a week or more to appear. Commonly delayed symptoms include:
- Persistent headache or pressure that shows up the next morning
- Memory problems or mental fog that was not obvious at first
- Sleep trouble starting one to two nights after the injury
- Mood changes — irritability, anxiety, or depression — developing over several days
- Light and noise sensitivity that gets worse rather than better
This delay is especially important in car accidents, slip-and-fall injuries, and construction accidents where the person seemed unhurt. If you or someone with you took a significant head impact, do not assume that feeling fine right after means there is no concussion.
Emergency Warning Signs: When to Call 911 or Go to the ER
Most concussions do not require an emergency room visit. But certain concussion symptoms point to a much more serious injury — such as bleeding in or around the brain — and need immediate medical attention.
Call 911 or go to the ER right away if you see any of these:
- One pupil noticeably larger than the other
- A headache that keeps getting worse, not better
- Slurred or abnormal speech
- Vomiting more than once
- Seizures or convulsions
- Loss of consciousness — even briefly
- Extreme drowsiness or inability to wake up
- Growing confusion or unusual behavior
- Weakness or numbness in the arms or legs
- Severe balance problems or difficulty walking
These signs suggest the brain may be under pressure from swelling or internal bleeding. Do not wait to see if they improve on their own.
Concussion Symptoms in Children: What Parents Should Watch For
Young children cannot always describe what they are feeling after a head injury. Parents and caregivers need to know the visible signs:
- Appearing dazed or stunned
- Moving clumsily or losing balance
- Answering questions more slowly than normal
- Changes in behavior or personality
- Unable to remember events right before or after the impact
- Crying more than usual (in infants and toddlers)
- A vacant, glassy look
Recovery takes longer in children. Most adults recover within a couple of weeks; children can take up to four weeks. Teens may take even longer. Before a child returns to sports or heavy schoolwork, a healthcare provider should clear them. The CDC recommends a gradual, step-by-step return to school to avoid making symptoms worse.
Post-Concussion Syndrome: When Symptoms Linger
Most people recover fully from a concussion. But for 10 to 20 percent of patients, symptoms persist past the normal recovery window. When concussion symptoms last longer than three months, doctors call the condition post-concussion syndrome (PCS).
PCS symptoms mirror standard concussion symptoms but do not fade. Common ones include:
- Persistent headaches
- Dizziness and balance problems
- Trouble concentrating or remembering
- Sleep disturbances
- Anxiety or depression
- Irritability
- Light and noise sensitivity
People at higher risk include females, teens and young adults, and those with a prior concussion or a history of anxiety or depression. Most people with PCS recover within three months. About 5 to 10 percent have symptoms that last six months or longer.
PCS can affect daily life, work, and relationships in real ways — which is why a concussion should never be treated as minor, even when it is labeled a "mild" TBI.
What to Do After a Suspected Concussion
If you or someone near you took a head impact and shows any signs of a concussion, follow these medically recommended steps:
- Stop the activity. Do not try to push through. A second impact while the brain is already recovering from a concussion can cause far worse injury.
- Tell someone. Do not be alone in the first 24 hours after a suspected concussion.
- See a healthcare provider. Even mild concussion symptoms need evaluation. Only a medical professional can diagnose a concussion and rule out more serious injuries.
- Rest — physically and mentally. Avoid screens, loud places, hard exercise, and tasks that require heavy concentration while you recover.
- Follow return-to-activity steps. Before going back to sports, demanding work, or driving, get medical clearance and ease back in gradually.
- Watch for the emergency warning signs listed above — and go to the ER without delay if any appear.
If your concussion resulted from someone else's negligence — a car crash, a fall on dangerous property, or a workplace injury — The Orlow Firm's Queens brain injury lawyers can explain your legal options in a free consultation.
Frequently Asked Questions About Concussion Symptoms
Can you have a concussion without losing consciousness?
Yes — and this is one of the most important things to know. Most concussions do not involve any loss of consciousness at all. Headache, confusion, dizziness, and memory problems are far more common and reliable indicators of a concussion. If someone passes out, that does indicate a more severe impact, but the absence of blackout does not rule out a concussion.
How long do concussion symptoms last?
Most adults recover from a concussion within a couple of weeks. Children typically take up to four weeks. Symptoms that last beyond three months are classified as post-concussion syndrome, which affects 10 to 20 percent of concussion patients. Recovery time also depends on age, prior concussion history, and overall health.
What are the signs of a serious concussion?
Signs that point to a more severe brain injury include one pupil larger than the other, a headache that keeps worsening, repeated vomiting, seizures, slurred speech, extreme drowsiness, or loss of consciousness. If any of these appear, call 911 or go to an emergency room right away. These symptoms may mean there is bleeding in the brain.
Can concussion symptoms appear days later?
Yes. Delayed onset is common. Symptoms like persistent headache, memory trouble, sleep changes, and mood shifts can surface 24 to 72 hours after the injury — and sometimes up to a week later. Anyone who took a significant head impact should be monitored for several days, even if they felt fine right after.
What does a concussion headache feel like?
A concussion headache is usually a dull, persistent pressure or throbbing sensation — not a sharp stabbing pain. It often comes with sensitivity to light and sound, nausea, and a feeling of mental fog. The headache may worsen with physical activity or concentration, which is the brain's signal to rest.
Sources & Official Resources
Health & Medical Sources
- Symptoms of Mild TBI and Concussion — CDC
- About Mild TBI and Concussion — CDC
- What to Do After a Mild TBI or Concussion — CDC
- Signs and Symptoms of Concussion — CDC HEADS UP
- Returning to School After a Concussion — CDC HEADS UP
- Postconcussive Syndrome — NIH/NCBI StatPearls
Contact The Orlow Firm
If you suffered a concussion in an accident caused by someone else's negligence — a car crash, a construction site injury, or a fall on a dangerous property — you may be entitled to compensation for your medical bills, lost wages, and pain and suffering.
The Orlow Firm has helped injury victims in Queens and throughout New York City since 1982. Call (646) 647-3398 for a free consultation. Se Habla Español.
Prior results do not guarantee a similar outcome.
