Suddenly, it’s there: a sensation of fear so overwhelming that it leaves you feeling as though the ground has been pulled from under your feet, accompanied by symptoms such as palpitations, shortness of breath or dizziness. A short time later, the terror's over, leaving you feeling helpless.

The physical symptoms of a panic attack can be so intense that people think they've had a heart attack. However, the symptoms often feel much more severe than they actually are. The reason for this is the emotional interpretation of the physical reaction. A person having a panic attack can interpret the increased heart rate as a heart attack, even though an ECG would not be able to detect any actual tachycardia.

No clear trigger

The triggers of panic attacks – if there are any – are as varied as the attacks themselves. Panic attacks often occur for no discernible reason. But certain situations, such as crowded places, noise, or feeling trapped, can increase the risk. What's also apparent is that people with certain conditions, such as depression, post-traumatic stress disorder and certain phobias, are at greater risk of having panic attacks.

It's estimated that two to three per cent of the population will experience one or more panic attacks in their lifetime. They're most common among people from their late teens to 30 years of age, with women being slightly more affected than men.