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.

Signs and Symptoms of Concussion

By

Rod Brouhard, EMT-P

Updated on July 15, 2021

Medically reviewed by

Nicholas R. Metrus, MD

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 a concussion is to divide them into types. The Centers for Disease Control and Prevention (CDC) lists four separate categories of concussion symptoms.

Cognitive symptoms: Trouble remembering new information, difficulty thinking clearly or quickly, confusion, 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: Unexplained irritability, sadness, nervousness, anxiety, or a general tendency to be more emotional than usual
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.

Complications

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.

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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.

Concussions: Causes and Risk Factors

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