Symptoms of Concussion

Man pushing his hair back
Credit: Cultura/Robin Skjoldborg/Riser/Getty Images

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.

Types of Symptoms

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

  • Cognitive Symptoms: This includes trouble remembering new information; difficulty thinking clearly or quickly; confusion; an inability to concentrate or focus
  • Physical Symptoms: Headache; blurred vision; nausea 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
  • Emotional Symptoms: A concussion can affect a person's mood, causing unexplained irritability, sadness, nervousness, anxiety, or a tendency to be more emotional than usual in general
  • Sleep-related Symptoms: Sleeping longer than usual or less than usual, or having trouble falling asleep; drowsiness

These symptoms can occur in kids too.

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

When to See a Doctor

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. 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. 

When a blow to the head causes any immediate symptoms, no matter how mild or fleeting they are he should stop whatever he is doing. Continuing an activity increases the risk of another injury, with potentially more severe repercussions. It's a good idea to follow up with a neurologist whenever there's the possibility of concussion or TBI.

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

Complications of Concussion

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 Radioneurology.

What's more, often immediate signs of concussion such as dizziness and disorientation 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.

One chronic problem related to multiple concussions that has received a lot of attention is depression. In one study of 2,552 retired pro-football players, for instance, more than 11 percent of those with a history of multiple concussions also had a diagnosis of clinical depression. Players reporting three or more previous concussions were three times more likely to be diagnosed with depression than those with no history of concussion.

Some research finds the prevalence of depression in head trauma patients can be as high as 40 percent. Several studies have also shown a link between a history of brain injury and a higher probability of developing major depression later in life.


American Society of Radioneurology. "Traumatic Brain Injury (TBI) and Concussion."

Centers for Disease Control and Prevention. "Traumatic Brain Injury and Concussion: Signs and Symptoms." Mar 22, 2017.

Pryor, J., Larson, A., and DeBeliso, M. "The Prevalence of Depression and Concussions in a Sample of Active North American Semi-Professional and Professional Football Players." J Lifestyle Med. Mar 2016. 6(1): 7-15. DOI: 10.15280/jlm.2016.6.1.7.