Signs and Symptoms of Concussion

Concussion symptoms are tricky. Signs of damage to the brain vary widely depending on factors such as the severity of the blow to the head or body and the location of the injury. For instance, a jolt to the back of the head, where the occipital region of the brain is, may produce dizziness or vision problems. An injury to the front of the head may produce personality or emotional disturbances.

To complicate things further, some concussion symptoms appear right away, while others may not show up for days or even weeks. That's why it's important to regard any blow to the head as potentially leading to a concussion, even if any immediate reactions such as dizziness or disorientation are mild or brief, and to keep an eye out for future symptoms that can appear well after the actual event.

concussion symptoms
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Types of Symptoms

One helpful way to look at the myriad symptoms of a concussion is to divide them into types. The Centers for Disease Control and Prevention (CDC) lists four separate categories of concussion symptoms.

  1. Cognitive symptoms: Trouble remembering new information, difficulty thinking clearly or quickly, confusion, inability to concentrate or focus
  2. Physical symptoms: Headache, blurred visionnausea or vomiting (these are two symptoms that are more likely to show up early), dizziness (vertigo), sensitivity to noise or light, problems with balance and coordination, fatigue, weakness, lethargy, or lack of energy
  3. Emotional symptoms: Unexplained irritability, sadness, nervousness, anxiety, or a general tendency to be more emotional than usual
  4. Sleep-related symptoms: Sleeping longer than usual or less than usual, having trouble falling asleep, or drowsiness

In very young children, concussions also may cause inconsolable crying and a refusal to eat or nurse. 


Even a mild head injury can result in significant problems in the long-term. This is especially true of multiple concussions which "have been linked to the development of delayed brain degeneration," according to the American Society of Neuroradiology.

Moreover, immediate signs of concussion such as dizziness and disorientation often are so mild and disappear so quickly, sometimes within minutes, that a person who experiences them will shrug them off. The problem is, any degree of trauma to the brain needs time to heal.

A chronic problem related to multiple concussions is depression. One study found that players with depression had sustained significantly more concussion than non-depressed players, and that greater than three concussions appeared to increase the symptoms of depression.

Some research has found the prevalence of depression in head trauma patients can be as high as 40%.

Several studies have also shown a link between a history of brain injury and a higher probability of developing major depression later in life.

When to See a Healthcare Provider

Although it can take some time for a concussion to bring about symptoms, in some cases it will be clear right away that a person may have a concussion or other traumatic brain injury (TBI).

For example, if a football player feels dizzy or disoriented after a tackle causes him to hit his head on the ground or he gets into a helmet-to-helmet collision with another player, he may have suffered a concussion even if he feels perfectly fine after a few seconds. 

If a blow to the head causes any immediate symptoms, no matter how mild or fleeting they are, stop what you are doing and seek medical attention.

It's a good idea to follow up with a neurologist whenever there's the possibility of concussion or TBI.

Concussion Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Man

When to Seek Emergency Care

There are obvious signs that emergency care is in order. If you or someone else experiences one or more of the following symptoms after sustaining a blow to the head, however minor it may seem, seek immediate medical attention for a complete evaluation.

  • Difficulty remembering recent events or personal information
  • A severe headache, particularly one that comes on quickly and in a specific location
  • Severe stiffness in the neck
  • Mental confusion or strange behavior
  • Nausea or vomiting
  • Dizziness, poor balance, or unsteady gait
  • Weakness in the arms or legs
  • Extreme drowsiness or sleepiness
  • Unequal pupil sizes
  • Loss of appetite
  • Persistent ringing in the ears
  • Slurred speech
  • Visual problems, such as seeing stars or blurred vision
  • Bleeding or clear fluid coming from the ears or nose
  • Convulsions
  • Loss of consciousness

Frequently Asked Questions

  • How long after a blow to the head do concussion symptoms appear?

    Typically, the symptoms of a concussion will be apparent immediately or soon after a head injury, but not always. It sometimes takes hours or days for symptoms to develop, as the damage to cells in the brain and resulting chemical changes may not trigger cognitive and other symptoms right away.

  • How is a concussion headache different from a migraine?

    Both types of headache can share many of the same symptoms, including nausea and/or vomiting, sensitivity to noise and light, and dizziness. The main difference between a migraine and what is known as a post-traumatic headache is the cause, with the latter obviously due to a brain injury. Also, concussion headaches tend to develop within seven days of a head injury and in some cases persist for years.

  • How can I tell if my child has a concussion?

    This will depend on how old your child is. Infants and toddlers do not have the language skills to describe how they're feeling, so parents will have to rely on changes in their behavior that can take time to develop. A child who has a brain injury may cry inconsolably, be fussy for no obvious reason, vomit, or not wake up easily.

  • How long do concussion symptoms last?

    Symptoms of a mild traumatic brain injury can last from several weeks to several months. During this time, it's important to rest when necessary but to begin to resume normal activity as you're able and according to your healthcare provider's instructions.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Symptoms of Traumatic Brain Injury (TBI).

  2. American Society of Neuroradiology. Traumatic Brain Injury (TBI) and Concussion.

  3. Pryor J, Larson A, DeBeliso, M. The prevalence of depression and concussions in a sample of active north american semi-professional and professional football playersJ Lifestyle Med. Mar 2016. 6(1): 7-15. doi:10.15280/jlm.2016.6.1.7

  4. Hart T, Hoffman JM, Pretz C, et al. A longitudinal study of major and minor depression following traumatic brain injury. Arch Phys Med Rehabil. 2012;93(8):1343-9. doi:10.1016/j.apmr.2012.03.036

  5. U.S. National Library of Medicine. Concussion.

  6. Cleveland Clinic. Concussion. Updated June 2, 2020.

  7. American Headache Society. Concussion, migraine and post-traumatic headache.

  8. KidsHealth from Nemours. Head Injuries.

  9. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Report to Congress on traumatic brain injury in the United States: Epidemiology and rehabilitation.

  10. Centers for Disease Control and Prevention. Getting better after a mild TBI or concussion.

Additional Reading

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.