Mild head injury and concussion

This information is for anyone who has had a mild head injury (also known as concussion or minor head injury) and their family and friends. The information will help both people in the early stages of recovery and those who experience ongoing problems.

In this section:

Visit our Concussion Aware campaign page for ways to raise awareness on concussion protocols in sport.

What is concussion?

Concussion is also often referred to as mild head injury, minor head injury or mild traumatic brain injury (mTBI). Regardless of the terminology used, the occurrence of a head injury in these cases causes the brain to shake back and forth inside the skull, causing mild damage.  

Concussion is commonly caused by falls, road crashes, assaults and sports accidents. While most mild head injuries result in no long-term damage to the brain, it can cause temporary disruption to brain function that can last for at least a number of weeks.

Mild head injury/concussion is defined by:

  • Loss of consciousness of less than 30 minutes (or no loss of consciousness)
  • Post-traumatic amnesia (PTA) of less than 24 hours after injury (this is a period where people are confused, act strangely and are unable to remember what has just happened)

It is important to note that only around 10% of reported mild head injuries/concussions involve a loss of consciousness – so it’s important to not solely rely on this as an indicator.

What are the symptoms of concussion?

Mild head injury can leave people with a range of concussion symptoms including dizziness, nausea, confusion or an inability to process or retain information, sensitivity to light, and vision distortion.

In some cases, an individual may lose consciousness as a result of the head injury, but it is important to note that only around 10% of reported concussions involve a loss of consciousness – so it’s important to not solely rely on this as an indicator.

In the early stages after a mild head injury, there is a small risk of developing complications that may require emergency treatment. Find out more about the warning signs below. 

While for most people concussion symptoms will resolve themselves in a few days or weeks, some people may find that they persist for much longer. Post-concussion syndrome is the name given to the range of symptoms that continue to occur following a mild head injury or concussion.

When should I seek medical advice after concussion?

After a concussion/mild head injury, it is important that, if possible, you are accompanied by a responsible adult.

While unlikely, there is a small risk of developing complications, so if you experience any of the following concussion signs and symptoms in the next few days you should go to your nearest Emergency Department as soon as possible:

  • Loss of consciousness 
  • Increasing disorientation
  • New deafness in one or both ears 
  • Problems understanding or speaking
  • Loss of balance or problems walking 
  • Blurred or double vision
  • Any weakness in one or both arms or legs 
  • Inability to be woken
  • Any vomiting 
  • Bleeding from one or both ears
  • Clear fluid coming out of your ears or nose 
  • Any fits (collapsing or passing out suddenly)
  • Drowsiness when you would normally be wide awake 
  • Severe headache not relieved by painkillers such as paracetamol

Dos and don'ts in the first few days after concussion

Dos Don'ts
DO make sure you stay within reach of a telephone and medical help in the next few days DON'T stay at home alone for 48 hours after leaving hospital
DO have plenty of rest and avoid stressful situations DON'T drink alcohol until you feel better
DO show this information to a friend or family member who can keep an eye on your condition DON'T take aspirin or sleeping tablets without consulting a doctor
DO take painkillers such as paracetamol for headaches DON'T return to work until you feel ready
DO find out more in our factsheet Mild head injury discharge advice (PDF) DON'T play any contact sport for at least three weeks without consulting your doctor
DO get further information on when to seek medical attention on the NHS website DON'T return to driving until you feel you have recovered. If in doubt, consult your doctor.

The information on this website should not replace a clinical examination. If you have not been examined then contact your GP or call 111. In case of a medical emergency, please call 999. 

Post-concussion syndrome (PCS)

The effects of a concussion can be anything but mild to the person concerned. The symptoms can include nausea, headaches, dizziness, impaired concentration, memory problems, extreme tiredness, intolerance to light and noise, and can lead to anxiety and depression. When problems like this persist, they are often called post-concussion syndrome.

What are the symptoms of post-concussion syndrome?

The symptoms of post-concussion syndrome may include:

  • Headaches
  • Irritability
  • Feelings of dizziness
  • Restlessness
  • Nausea
  • Impulsivity and self-control problems
  • Sensitivity to light
  • Difficulty concentrating
  • Sensitivity to noise
  • Feeling depressed, tearful, anxious
  • Sleep disturbance
  • Fatigue
  • Memory problems
  • Difficulties thinking and problem-solving

How long does post-concussion syndrome last?

In many cases these symptoms resolve themselves within a few days or weeks. However, in some cases problems can persist for months, but still resolve themselves eventually. This can be a frustrating time, as the effects may be subtle and you may not have been told about them.

This may also be the most prolonged period of feeling ill that you have experienced and you may wonder if you will ever feel better. Following the suggestions in our booklet Mild head injury and concussion (PDF) should help to make you feel better as quickly as possible, but be patient with yourself and try not to rush things.

It is important to realise that these symptoms often happen even when there is no damage to the brain and that the fear of having brain injury, even if there is none, can be very distressing and can delay recovery. So it is sensible, if you have these symptoms for more than about two weeks after the injury, or if they are severe and not getting any better, that you see your GP.

It may be appropriate to be referred to a head injury specialist, such as a neurologist or neuropsychologist, for assessment. 

Managing concussion

While there is no single treatment for concussion, with appropriate medical care, plenty of rest and specialist support where appropriate most people will make a good recovery.

It is important that relatives and employers are warned about the possible effects of a mild head injury/concussion, and for plans to be made accordingly. These might include not rushing to return to work, keeping stress to a minimum in the short term, and abstaining from alcohol.

One study showed that almost one third of people with a mild head injury were not working full-time three months after receiving the injury, although other studies have been much more optimistic. Difficulties are certainly made much worse if the person has a mentally demanding job where there is a low margin for error.

Our booklet Mild head injury and concussion (PDF) provides tips and strategies for coping with the effects of post-concussion syndrome. 

Concussion in sport

Sport plays a key role in keeping us fit and healthy, with team sports in particular providing a host of additional benefits including social interaction and, instilling discipline and teamwork in young people.

As with in life in general, however, accidents and collisions can occur in contact sports – with head injuries commonplace in sports such as football, rugby, hockey and many others. And while rules are in place in such sports to protect players from head injuries, collisions are inevitable in contact sports.

Concussions are notoriously difficult to identify, particularly in the midst of a sports match. It can be an evolving condition, with the symptoms taking time to display themselves, while many of the symptoms require honesty from the individual (feelings of nausea, vision distortion etc.).

Concussion – or minor brain injury – in simple terms, is a temporary disturbance in the brain’s functioning as a result of a blow to the head.

Given the difficulty in identifying concussion and the risks of continuing to play once one has been sustained, the message has to be if in doubt, sit it out!

Basic assessment tools are freely available on the internet, including the most widely-used Sideline Assessment Concussion Tool (SCAT) – see

However, while this contains useful information, it should only be used as a diagnostic tool by medical professionals.

If any of these symptoms are experienced following a blow to the head, the player must be removed from the game to seek medical attention and not be allowed to return to the field of play.

Graduated return to play (and training) protocols must then be observed, with a player only commencing physical activity once he or she has received medical clearance to do so.

It is vital that all who participate in or watch sport are aware of the risks of concussion – particularly those involved at a grassroots or junior level, where ambulances and medics are not on standby should something go wrong.

What are the risks of ignoring concussion?

While injuries to external parts of the body can be identified, it is impossible to know what damage has occurred in the immediate aftermath of a head injury. Concussion is an evolving injury and the symptoms may be delayed in their presentation.

In the majority of cases, there will no long-term damage caused by a concussion – if treated appropriately with rest and medical assessment. Occasionally, complications can arise from seemingly minor blows to the head, which is why it is vital that people seek medical attention following a concussion.

There are significant risks in returning to the field of play after sustaining a concussion. If a player sustains another blow to the head before the brain has had a chance to recover from the initial concussion, the damage can be exacerbated to the point that it can be – on rare occasions – fatal. This is known as Second Impact Syndrome and it is believed to be most common among children and young adults.

In addition to putting themselves at risk of sustaining a more serious brain injury by returning to the field of play following a concussion, players are more susceptible to other injuries as they will not be able to perform at their best – either physically or cognitively.

Concussion myth busters

Someone steps on two arrows, one pointing to FACTS and one to MYTHS

Concussion is now far more widely discussed and acknowledged as an issue, but according to Headway, there is still a long way to go in terms of educating people around the dangers of concussion.

To help, we’ve busted some of the most common myths out there…

“I didn’t lose consciousness, so surely it couldn’t have been concussion?”

This is a common misconception. A person does not need to have lost consciousness to have experienced a concussion. In fact, less than 10% of concussions result in loss of consciousness. Following a significant impact to the head, some important signs to look out for that may indicate a concussion are confusion, dizziness and forgetfulness.

“I don’t want to let my team down by being removed from play if I have a concussion.”

If there is any suspicion of concussion, it is important to take an if in doubt, sit it out approach. Pushing on through a game can make the impact of a concussion worse. Paradoxically, doing so can jeopardise a team’s chance of success even more because the concussed player may not perform as well as normal. There is also a risk of secondary impact syndrome, by which a second incident of concussion can make the outcome much worse than if the person had sat out instead. It is important to put your health first and foremost, and your team and coach will support you with this.

“My friend had a concussion and they were fine after a week. I’ll probably be fine if I get a concussion too.”

It is important to remember that no two brain injuries are ever the same and experiences will vary from person to person depending on things such as the force of the impact, location of injury and personal differences. Whereas one person may recover from concussion after a week, others may have ongoing difficulties. Concussion management guidelines for sports suggest the minimal time for how long a player should rest after concussion, but it is important to assess each case differently and follow what your own body is telling you about how you feel.

“I hit my head when I got concussion. Surely that doesn’t mean I have brain injury?”

A concussion happens when a force to the head causes the brain inside to shake around the skull. Technically, this is considered a brain injury although it is classified as a minor brain injury. The terms minor brain injury, mild traumatic brain injury and concussion are often used interchangeably to reflect the nature of it being an injury to the brain, albeit not in the range of moderate or severe.

“You have to hit your head to have a concussion.”

Most concussions – particularly those occurring in sport – will result from a blow to the head. However, they can also occur as a result of the rapid acceleration/deceleration of the body, for example in a car crash, as the brain moves rapidly inside the skull.

“If you don’t have any symptoms immediately, you don’t have a concussion.”

Symptoms of concussion can often be delayed in their presentation and may not manifest for several hours or even days after the incident. In the meantime, however, you remain at risk of exacerbating the initial injury to your brain with any subsequent blow to the head you receive, hence the importance of following Headway’s message of ‘if in doubt, sit it out!’.

“You can return to play as soon as you feel better.”

If you have sustained a concussion or suspected concussion, it is vital that you do not return to play or training until cleared to do by a medical professional – even if you feel fine. The advice is to leave it at least three weeks before returning to play, follow your sport’s return-to-play protocols in the process.

Recovery from concussion and further information

The general conclusion seems to be that the vast majority of people who experience a mild head injury make a full recovery, usually after 3-4 months. However there is a very small sub-group whose recovery is not so good.

See our booklet Mild head injury and concussion (PDF) for more details, and our factsheet Mild head injury discharge advice (PDF) for important information after sustaining a head injury.

If you would like to discuss any issues relating to mild head injury and concussion, please contact our helpline on 0808 800 2244 or