Panic disorder
As with many mental health conditions, the exact cause of panic disorder isn't fully understood.
It's thought that panic disorder is probably caused by a combination of physical and psychological factors. Some of these factors are outlined below.
A trauma, such as bereavement, can sometimes trigger feelings of panic and anxiety. These feelings may be obvious soon after the event or they may be triggered unexpectedly years later.
Having a close family member with panic disorder is thought to increase a person's risk of developing it. However, the precise nature of the risk isn't known.
Neurotransmitters are chemicals that occur naturally in the brain. It's thought that an imbalance of these chemicals may increase your risk of developing conditions such as panic disorder.
Some experts believe that panic disorder is linked to an increased sensitivity to carbon dioxide. Breathing in air with high carbon dioxide levels can bring on panic attacks, and breathing techniques can help to relieve or stop panic attacks.
Another theory is that people who experience panic attacks tend to focus on minor physical symptoms and interpret them in a catastrophic way. This triggers a nervous system response that causes the panic attack.
Panic disorder is where you have recurring and regular panic attacks, often for no obvious reason.
The symptoms of a panic attack can be very frightening and distressing. They tend to occur very suddenly, without warning and often for no apparent reason.
As with many mental health conditions, the exact cause of panic disorder isn't fully understood.
Everyone who has panic disorder will experience panic attacks. However, not everyone who has panic attacks is diagnosed with panic disorder.
The main aim in treating panic disorder is to reduce the number of panic attacks and ease the severity of symptoms.
If you have panic disorder, there are several self-help techniques you can use including slow, deep breathing, relaxation techniques and visualisation.
Panic disorder is a treatable condition, but to make a full recovery it's very important you seek medical help as soon as possible.
Colin Hammond describes how panic attacks affected his life and became a series of phobias and anxieties, and how therapy helped his recovery.
Claire Ledger had her first panic attack while shopping in her local high street.