Symptoms and causes

Symptoms

Post-concussion symptoms include:

  • Headaches
  • Dizziness
  • Fatigue
  • Irritability
  • Anxiety
  • Insomnia
  • Loss of concentration and memory
  • Ringing in the ears
  • Blurry vision
  • Noise and light sensitivity
  • Rarely, decreases in taste and smell

Post-concussion headaches can vary and may feel like tension-type headaches or migraines. Most often, they are tension-type headaches. These may be associated with a neck injury that happened at the same time as the head injury.

When to see a doctor

See a doctor if you experience a head injury severe enough to cause confusion or amnesia — even if you never lost consciousness.

If a concussion occurs while you're playing a sport, don't go back in the game. Seek medical attention so that you don't risk worsening your injury.

Causes

Some experts believe post-concussion symptoms are caused by structural damage to the brain or disruption of the messaging system within the nerves, caused by the impact that caused the concussion.

Others believe post-concussion symptoms are related to psychological factors, especially since the most common symptoms — headache, dizziness and sleep problems — are similar to those often experienced by people diagnosed with depression, anxiety or post-traumatic stress disorder.

In many cases, both physiological effects of brain trauma and emotional reactions to these effects play a role in the development of symptoms.

Researchers haven't determined why some people who've had concussions develop persistent post-concussion symptoms while others do not. There's no proven connection between the severity of the injury and the likelihood of developing persistent post-concussion symptoms.

However, some research shows that certain factors are more common in people who develop post-concussion syndrome compared with those who don't develop the syndrome. These factors include a history of depression, anxiety, post-traumatic stress disorder, significant life stressors, a poor social support system and lack of coping skills.

More research is still needed to better understand how and why post-concussion syndrome happens after some injuries and not others.

Risk factors

Risk factors for developing post-concussion syndrome include:

  • Age. Studies have found increasing age to be a risk factor for post-concussion syndrome.
  • Sex. Women are more likely to be diagnosed with post-concussion syndrome, but this may be because women are generally more likely to seek medical care.