8 Concussion Symptoms You Should Know

Having a concussion can be more than just losing consciousness.

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A concussion is a type of brain injury that usually has a short-term loss of brain functioning, per MedlinePlus. Even after recovery, concussions can have long term consequences, according to the American Association of Neurological Surgeons (AANS), such as mood swings, fatigue, insomnia, or changes in personality.

But considering that there's currently no definitive, objective exam for concussion—they don't show up on MRIs or CT scans—recognizing the symptoms is how they're identified whether you, a friend, or your physician makes the call.

"If you have a certain set of symptoms, you can be reasonably certain you have a concussion," explained Kenneth Podell, PhD, director of Houston Methodist Concussion Center. It's important to realize that symptoms may be sudden and acute or may be subtler and worsen over the next couple of days, Podell added.

To ensure you get the right medical attention after a concussion, here are eight signs to look for so you can get the help you need.

01 of 09

Loss of Consciousness

If you are knocked out or, while alone, come-to without even realizing you were knocked out and don't remember how you ended up on the ground, a concussion may be the issue.

However, it's important to note that you can get a concussion even if you aren't knocked out completely. Also, "[i]nterestingly, being knocked out doesn't mean you have a more severe concussion than if you weren't knocked unconscious," said Chris Hummel, clinical professor and chair of Ithaca College's Department of Exercise and Sport Sciences.

02 of 09

A Headache That Just Won't Quit

Hitting your head or getting hit in the head is bound to hurt and leave you with a headache. If you have a concussion, however, that headache won't go away, and it will likely feel different from those you've had in the past, said neurologist Barry Kosofsky, MD, of New York Presbyterian/Weill Cornell Medicine.

"It's like a pressure headache that is nearly constant. It may get worse when you lie down and a little better when you stand up," Dr. Kosofsky said. "It also is inducible by increased blood flow to the brain. So doing mental or physical activities that bring more blood into the brain will cause pain."

03 of 09

Dizziness, Feeling Off-Balance, or Nausea

Being dizzy or off balance is a common symptom of concussion, so much so that balance testing is a regular assessment tool for diagnosing the injury as well as for evaluating recovery.

If your head is spinning and you're stumbling around, those are red flags signaling concussion, Hummel said. But even subtle symptoms like feeling unsteady on your feet can indicate a brain injury. In some cases you may also feel sick to your stomach or vomit after you've hit your head—both of which are symptoms of a concussion.

04 of 09

Fogginess or Confusion

Feeling foggy or confused are signs of concussion, Dr. Podell said. For mild traumatic brain injuries (TBIs), cognitive impairment has included experiencing issues with processing speed, attention, or episodic memory (long-term memory recall of previous events), noted by researchers in a February 2021 Scientific Reports study.

The effects can be profound, such as not knowing which way is home, or more subtle problems with processing information. Having trouble remembering things; being unable to concentrate or pay attention; or having more trouble than usual organizing your daily tasks, solving problems, or making decisions are all signs that you've injured your brain.

05 of 09

Blurry Vision or Eyes Hurting From Bright Lights

If you're having trouble focusing using your eyes, it's very probable that you have a concussion. Double or blurry vision is a symptom, as is light sensitivity. "If all the sudden the world seems too bright and light is really bothering you, that's a sign of concussion," Hummel said.

06 of 09

Feeling Anxious, Irritable, or Just Not Like Yourself

Feeling anxious is a common symptom of depression, as are other personality changes like irritability. But depending on your circumstances, these can be trickier to pick up in yourself.

Additionally, pay attention if others point out any personality changes, Hummel said. "Someone who knows you well can pick out subtle changes in your personality like you're usually pretty happy-go-lucky, but now you're more quiet and withdrawn—that can signal a brain injury," Hummel added.

07 of 09


Fatigue is a frequently-reported symptom of those who had a TBI, per a July 2020 Journal of Neurology study.

It takes a lot of energy to heal an injured brain, so it's very common to feel drowsy, listless, and downright lethargic afterward. "Physical and cognitive rest during the first 24 to 48 hours is essential for proper concussion healing," Hummel said. Along those lines, keeping someone awake after a concussion is no longer recommended—MedlinePlus noted that getting rest and sleeping is the first thing to help with recovery.

Hummel also recommended that you find someone to stay with you if you live alone for the first 24 hours after the injury. This is in case you develop symptoms of a life-threatening hematoma, such as loss of consciousness, inability to be awakened, or a worsening severe headache.

08 of 09

Sleep Issues

Though you may feel totally wiped out, you also may find that you can't sleep well at night after a concussion. Sleep issues following brain injuries have been fairly common: An April 2016 study published in Neurology: Clinical Practice indicated that between 30% and 70% of people reported having problems with sleep after a TBI.

09 of 09

Dangerous Concussion Symptoms

Though a concussion requires medical attention, there are signs of a concussion to which you'll want to pay special attention, according to the Centers for Disease Control and Prevention (CDC). These symptoms might entail:

  • Slurred speech
  • Weakness or numbness
  • Pupil size differences in the eyes
  • A headache that continues to get worse
  • Decreased coordination
  • Drowsiness or an inability to remain awake
  • Repetitive vomiting or nausea
  • Convulsions or seizures
  • Unusual behavior

For infants and toddlers, other symptoms to look out for beyond the ones listed are if the child does not stop crying, cannot be calmed, or refuses to eat or nurse. If any of these symptoms occur, call emergency medical personnel immediately.

Finally, trust your instincts and don't second-guess yourself when it comes to your brain, Hummel added. Symptoms of concussion can be obvious and show up immediately, or they can appear days—or weeks—later. "If you've hit your head hard and feel off and it crosses your mind that you could have a concussion, chances are pretty good that you do. Go get yourself checked out to be safe."

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