We all seem to have heard of post-traumatic stress disorder (PTSD), but many of us will be lucky enough never to experience it. This can mean that it's quite hard for us to fully appreciate what it is and how it can affect people.

While PTSD affects people in different ways, it is damaging no matter what and can have long-term impacts. There are a lot of things that can cause it and – just as with other mental illnesses – a variety of symptoms.

But what exactly is PTSD? 

To put it simply, PTSD is a mental health disorder, which is developed after experiencing a traumatic event. For some, this could be a life-threatening event, such as combat, natural disaster or an accident. However, you can develop PTSD after witnessing any traumatic event, with some people being diagnosed with it after difficult births, assaults and abuse.

It may manifest fairly quickly after a traumatic incident or develop over time. Either way, it is a very serious condition and those experiencing symptoms should seek medical help as soon as possible in order to start treatment.

What does PTSD do?

There are a number of different PTSD symptoms and there's no real telling which symptoms someone may experience. 

Common symptoms include things like nightmares and flashbacks, insomnia and trouble concentrating. People can also experience feelings of guilt, isolation and irritability, which can affect an individual as well as the people around them.

There is no way of telling which symptoms may manifest, but they can be incredibly severe, impacting every aspect of someone's life. It isn't a case of ignore the symptoms and the problem will go away, as not dealing with PTSD can mean it gets worse over time.

People can also suffer from Complex PTSD, which is when they have experienced traumatic situations repeatedly. While symptoms are similar to standard PTSD, they may not manifest until years after an event.

How many people suffer from PTSD?

The NHS estimates that one in three people who have had a traumatic experience will experience some form of PTSD during their life. Not everyone who experiences trauma will develop the condition, even if two people witness the same event. 

It isn't clear what causes some to develop PTSD when others don't, but it is important to understand that it has nothing to do with strength or weakness and having the condition does not say anything about the type of person you are.

What can you do?

If you suspect you are or that someone you know is suffering from PTSD it is important that you or they visit their GP. While you can expect to deal with some confusing emotions or thoughts in the weeks following a traumatic event, if you experience any of the symptoms listed above beyond four weeks after the event, you may need help.

PTSD can be treated effectively, so it is never too late to seek help, although the sooner you see a doctor after experiencing symptoms, the sooner you can begin a course of treatment.

Don't be embarrassed about seeking help if you need it, as it will benefit you in the long run and keep you healthy.

If you know someone with PTSD, it is important to be as supportive and patient as possible as everyone deals with it in different ways.

Where can you go?

As well as seeing your GP and seeking medical treatment, there are charities and organisations that can help servicemen and women and veterans deal with their PTSD. Combat Stress is the leading mental health charity for veterans and could be a good place to start.