Motion sickness is a nightmare for travellers who are susceptible to it. It can occur when the sensory inputs about body position contradict what is expected. Motion sickness can be provoked by abrupt changes in movement that occur during bumpy rides, turbulent flights and rough seas. It can also occur when one is exposed to moving visual scenes while the body is in a relatively fixed state.
According to experts, almost everyone will get motion sickness if the conditions are extreme enough. But generally about one-third of the population is highly susceptible to motion sickness, a third experiences it in fairly rough conditions and the other third becomes sick only in extreme conditions.
Some groups seem particularly susceptible to motion sickness including children aged three-12 years, people who experience migraine, and women particularly during menstruation and pregnancy. A large study (535 subjects) done in India, found the prevalence of motion sickness was about 27 per cent.
The first documented evidence of motion sickness is in ancient Greek literature from the early days of seafaring history. And it is interesting to note that the English word nausea comes from the Greek word for ship (naus), which is also the origin of the word “nautical”.
Features: All of us have probably had some form of motion sickness at one time or the other. It is an acute condition of medical distress that results in skin pallor, restlessness and cold sweat. It often starts as stomach discomfort. In later stages, nausea, excessive salivation and vomiting occur. The degree of symptoms depends upon the susceptibility of the person and intensity of stimuli.
Aetiology
The precise aetiology is a mystery but there are some theories:
Classic Sensory Conflicts: Motion sickness occurs when there is a mismatch of messages delivered by vestibular receptors, eyes and proprioreceptors in the skin muscles and other tissues. Sensory signals conflict with each other and the brain’s positional memory.
As an example, if you are travelling in a car and reading a book, your inner ear and skin receptors will detect that you are moving forward. However, your eyes are looking at a book that isn’t moving and your muscle receptors are telling your brain that you are sitting still. So the brain gets a little confused. Things may begin to appear a little scrambled inside your head – and you get motion sickness.
Postural Instability Theory: In experiments, it was found that motion sickness was usually preceded by a statistically significant increase in several indices of postural sway. In these cases, motion sickness symptoms were not linked to sensory conflict, but rather to a decreased ability to actively control body’s postural motion.
How To Help
While medication may be an acceptable treatment for travellers who experience motion sickness occasionally, the goal for individuals who experience motion sickness on a regular basis or whose work is affected by their symptoms is to learn to control and eventually prevent these symptoms.
How To Prevent Motion Sickness
• Watch your consumption of food and drink before and during travel. Eat a light meal no less than three hours before exposure. Avoid excessive smoking and disagreeable odours. Avoid dairy products and foods high in protein calories and sodium before starting the journey.
• Stay occupied to distract your mind from thinking about motion sickness.
• Avoid visual stimuli (reading, watching videos) as they make you more prone to motion sickness.
• Choose a seat where you will experience the last motion. Do not sit facing backwards from your direction of travel. When travelling by car, it helps if you keep your gaze fixed on the horizon or look to a distant point.
• Reduce anxiety and fear. Some individuals are naturally prone to motion sickness but fear or anxiety can promote symptoms.
• Isolate yourself from others who may be suffering from motion sickness. Hearing about motion sickness or seeing others becoming ill can sometimes make you feel ill yourself.
• Limit head movements (for example pressing your head into the headrest).
• Increase ventilation or exposure to cool, fresh air.
Caution About Medications
Medications should be taken after consulting your physician: Medications for motion sickness may cause drowsiness and impair judgement and therefore should be avoided by pilots, astronauts, ship crew-members and any person in the occupation where he or she uses machinery. In such cases, biofeedback training and relaxation and cognitive behaviour therapy can be useful.
Biofeedback training and relaxation: In a study of 55 pilots who had to stop flying due to symptoms of motion sickness 76 per cent of them successfully overcame their motion sickness and returned to work after participating in a biofeedback training and relaxation programme. Pilots were exposed to a stimulus that caused motion sickness (sitting in a tilting rotating chair). While sitting in the chair the pilot performed various relaxation techniques such as deep muscles relaxation and mental imagery.
After some time when the pilots where habituated to the rotating chair, they no longer felt sick because they learnt to relax in it.
Cognitive Behaviour Therapy: The goal of this therapy is to alleviate the anxiety that some people experience simply thinking about motion sickness. In a study of 50 pilots who occasionally experienced motion sickness, 86 percent of them successfully overcame their symptoms after cognitive behaviour therapy.
Breathing technique: Taking slow, deep breaths can reduce symptoms.
Have a safe and happy travel!
