Travel sickness can spoil a day out. Catherine Cronin roots out explanations and remedies.
She counts cars and Formula 1 among her passions and ever since passing her driving test, Patricia Ortiz has to take the driver's seat, especially on winding hilly roads.
She suffers from travel sickness, and taking the wheel often keeps it at bay.
Ortiz is Spanish, but has lived in Ireland for nearly 15 years. A director of an art restoration company, she regularly drives country-wide to work on client projects
"I've had it since I was eight, though it only sets in when I'm a passenger in a car travelling on extremely winding roads or those with very undulating surfaces. I don't look forward to the road to Glendalough, the stretch from Macroom to Gougan Barra, or the run-in to Edenderry from Enfield, though I'm fine when I'm driving.
"It's much worse in Spain - Almeria, where I grew up, is very mountainous. I no longer take the family trip to a neighbouring village, Enix, 20 minute drive away but at a much higher elevation. Locals go there in summer to get away from the sweltering heat, but it's 20 minutes of hairpin curves all the way.
"When travelling there, I have to keep looking outside, car windows open. I get hot, feel suffocated and queasy and have to ask the driver to stop for an air break.
"I can't eat at the end of the trip and, unlike in Ireland, doing the driving myself is only a slight improvement. So I just avoid the trip altogether.
"Generally it's much worse in jeeps - I can feel the turns and bends more. It's also worse in cars with suspensions that really let you feel the road."
Motion sickness can afflict anyone travelling by land, sea or air. With the holiday season approaching, awareness can go along way to preventing it, explains Dr Martin Daly, a GP in Ballygar, Co Galway.
"A variance between what the eyes see and what the body senses sends conflicting signals to the brain," he explains. "When reading in a moving car, one part of the balance system, the inner ear, detects motion, but the eyes which are focused inside the car do not. The conflicting signals cause nausea."
Anyone travelling can potentially succumb to it. Sufferers have included Lord Nelson on his voyages, Lawrence of Arabia on the camel, soldiers in armoured personnel carriers (APC), over half the student pilots in the US air force - and, reportedly, the Minister for Transport, Martin Cullen.
Soldiers at the back of an enclosed APC feel movement over difficult terrain but see nothing. To reduce the likelihood of sickness, convoys make hourly stops.
In pilot training, G-loads and aerobatic manoeuvres are increased gradually to allow the body adapt to it, according to a spokesperson for the Defence Forces.
The US air force air sickness programme emphasises diet and flight simulation in learning to overcome sensory conflict.
About one in every five suffers from car sickness. Over half are under 16 years so most families will come across it, though children can grow out of it over time, says Dr Daly.
It usually starts with mild nausea, cold sweat, fatigue and loss of appetite in adults. Restlessness, pallour, crying and yawning are the clues in children before the sick bag is needed.
"The emphasis should be on prevention," says Daly. "It can often be avoided by simple measures. What the person is looking at is most important.
"Adults should sit up front, concentrate on looking out, ideally towards the middle-distance or horizon - and they should avoid heavy, greasy or spicy foods. Driving keeps the focus outside so this can help some.
"For children, anything that requires looking out a window is good. Some cars have raised seats in the back to prop them up allowing them see outside.
"It's also a good idea to keep chatting to them, and be aware that strong odours like perfumes can also trigger it."
Should these steps not work, there are over-the-counter medicines which help prevent it, he says. Some people find alternative remedies such as ginger helpful.
For many people such as Patricia Ortiz, car sickness is more an annoyance than anything else. But in severe form it can be very debilitating.
Passengers who have been car sick before usually anticipate becoming ill, making journeys worse still, according to Daly.
An ominous note arises from an RAC Foundation survey in Britain - it found that drivers were easily distracted when someone became car sick and could drive recklessly to finish the journey more quickly.