Martina McElligott, director of Out and About (OANDA), the support group for people with phobias and anxiety disorders, says a phobia can affect anyone and may stem from a childhood incident or a lifechanging event.

"Any kind of incident can lead to a phobia, particularly when a person is under stress and there is an exposure to fear, " she said. "For instance, if a person is involved in a car accident, they may develop a phobia of driving, or if they are bitten by a dog as a child, they might have a fear of dogs."

A recent report by the National Phobics Association in the UK found that a phobia dominates the daily lives of rising numbers of people, with one in eight people suffering from a phobia in their lifetime.

People can develop specific phobias about anything from buttons and bananas to public toilets, lifts and spiders.

"A person can develop a phobia of absolutely anything, even the green part of a tomato, " said McElligott, a cognitive behavioural therapist. "There doesn't need to be a logical reason as to why they might have such a fear but very often people are too ashamed to come forward and seek help. A phobia is something that is very treatable and it's important to get treatment before it becomes a long-term and more crippling condition."

A phobia differs from a fear in that it is usually irrational.

When confronted with the object of their phobia, sufferers may have an overwhelming urge to get as far away as possible, have difficulty breathing and a racing heartbeat.

The condition is often treated with anti-depressants but, McElligott says, unless someone is depressed, therapy should be the first treatment.

"Medication should be the last port of call, " she said.

Agoraphobia, the fear of social situations, is the most common phobia in Ireland, followed closely by claustrophobia (fear of enclosed spaces), arachnaphobia (spiders), cynophobia (fear of dogs) and aviatophobia (fear of flying).