Think of panic, particularly a panic attack, and the image is most likely to be of something sudden, shocking and uncontrollable.

However, new research suggests that the body starts to 'warm up' for panic attacks more than an hour before their onset.

Psychologist Alicia E Meuret of Southern Methodist University in Dallas used portable recording devices to measure the bodily functions, including breathing and heart rate, of panic attack sufferers around the clock.

She found that physical symptoms too small to be perceived by her subjects built up towards the onset of attacks.

"The results were just amazing," Meuret said. "We found that in this hour preceding naturally occurring panic attacks, there was a lot of physiological instability. These significant physiological instabilities were not present during other times when the patient wasn't about to have a panic attack."

Although panic attacks are diagnosed as psychological disorders, the symptoms are overwhelmingly physical: 10 - shortness of breath, heart racing, dizziness, chest pain, sweating, hot flashes, trembling, choking, nausea and numbness - as against three - feeling of unreality, fear of losing control and fear of dying - psychological.

Meuret attached monitors to 43 patients, collecting nearly 2,000 hours or data. The subjects pressed a button when a panic attack came on.

The research has also verified a long-held suspicion that high carbon dioxide levels may contribute to panic attacks and sufferers are likely to be chronically hyperventilating.

"We found 15 subtle but significant changes an hour before the onset of the panic attacks that followed a logical physiological pattern. These weren't present during the non-panic period," Meuret said.

"Why they occurred, we don't know. We also can't say necessarily they were causal for the panic attacks. But the changes were strikingly and significantly different to what was observed in the non-panic control period," she said.

Meuret argues that the research will help sufferers deal with panic disorder and will also have applications in other apparently sudden-onset conditions. Meuret published the study in the journal Biological Psychiatry.

Top Image Credit: © Ioannis Pantzi