Do you often get motion sickness when traveling in any mode of transportation? If the answer is yes, it is possible that you suffer from kinetosis, a disorder also known by other names such as travel sickness or sea sickness. If this is your case or you know someone who suffers from it, read on to find out what motion sickness is, how it is related to your genes, what are its symptoms, its causes and what remedies exist to prevent it.
What is motion sickness?
Kinetic dizziness or motion sickness is a clinical picture comprising a set of symptoms including pallor, nausea, cold sweat and vomiting [1]. This symptomatology appears mainly associated with the movement of means of transportation and can affect anyone, especially children, pregnant women and people taking certain medications [2].
It is a normal physiological response that our body adopts when faced with an unusual perception of movement. It is included in “physiological vertigo”, as it is suffered by healthy people in a vertiginous environment [1], and should not be confused with “vertigo” which would imply an illusory sensation of movement in the absence of movement.
Symptoms of motion sickness
In addition to the more usual symptomatology, which includes pallor, nausea, cold sweat and vomiting, there is another series of symptoms that are also associated with motion sickness such as dizziness, headache, fatigue and drowsiness. Shortly before vomiting occurs, one may also feel increased salivation, aerophagia (swallowing excess air) and increased respiratory rate that may trigger hyperventilation and a feeling of impending fainting [3].
All of these symptoms of kinetosis usually subside when the motion that is causing the discomfort is stopped or when disembarking from the mode of transport that is causing the discomfort. Even on prolonged journeys, such as boat trips, people suffering from motion sickness may experience relief of symptoms as they adapt to the motion. Today, for example, stabilizing mechanisms are available on ships to minimize swaying.
Causes of motion sickness
One of the main causes of motion sickness is overstimulation of the areas of the inner ear responsible for controlling balance. This occurs when there is too much movement. Another of the causes related to the appearance of the symptoms of this ailment is related to the brain. In this case, the signals sent by the movement sensors to the brain (eyes, semicircular canals of the ears and muscle sensors) arrive in a contradictory way [3].
To visualize this more clearly, we can imagine a boat trip. While the person feels that they are still and even their references, such as the walls, are not moving, the boat is performing rocking movements. As what is perceived does not coincide with what is felt, the brain receives the contradictory information that causes the symptoms of motion sickness.
On the other hand, if we observe something that is moving too much, it is also possible that the brain misinterprets the information and triggers a response from the organism that includes all the symptoms mentioned above. This happens, for example, when we watch a movie shot with a moving camera or play a first-person video game.
There are several factors that can influence the appearance of motion sickness, these are:
- Sex, being women more susceptible to dizziness, which are also influenced by hormonal changes, having greater sensitivity during menstruation and pregnancy.
- Age. The susceptibility to dizziness increases during childhood, reaching its maximum peak around 10-12 years of age.
- Genetics. A large number of genetic variants have been described that increase predisposition to motion sickness, most of them associated with inner ear development, neurological processes and glucose homeostasis.
Treatment for motion sickness
There are a number of treatments to prevent and alleviate the symptoms of kinetosis. For travel, there are a number of behavioral recommendations that have been shown to be effective, such as [1]:
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- Eat something light and in small quantities before starting the trip.
- Position yourself in the more stable areas of the means of transport.
- Keep your eyes focused on the direction of travel.
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- Do not fix your eyes on a book or electronic device.
- Try to travel at night to sleep or at least have less visual stimulation.
- Do not drink alcoholic beverages.
As for the pharmacological treatment for motion sickness, there are over-the-counter medications designed to prevent motion sickness during travel. The pharmacist can advise you which one to use, but it is advisable that it be prescribed by a doctor who knows the individual situation of the person and can adapt the medication more effectively.
Common medications to prevent motion sickness include scopolamine, cyclizine, dimenhydrinate, diphenhydramine, meclizine and promethazine [3]. All of them can cause drowsiness and should be taken before the start of the trip or situation that may trigger symptoms.
Cinetosis and 24Genetics
In 2015, the first study linking motion sickness to a number of genetic variants was published. It noted that up to 70 percent of the variation in risk for motion sickness is due to genetics [4]. If you want to know if your propensity to suffer from this disease is in your genes, you have the option to take our DNA health test and find out. All our experts will be at your disposal to answer your questions before and after the test.
Bibliography
[1] What is motion sickness and how does it originate? – Laboratorios Normon España [published Jun. 2021; accessed Dec. 2022] Available from: https://www.normon.es/articulo-blog/que-es-la-cinetosis-y-como-se-origina
[2 ]MedlinePlus in Spanish [internet]. Centers for Disease Control and Prevention [accessed Dec. 2022] Available from: https://medlineplus.gov/spanish/motionsickness.html
[3] Motion sickness (seasickness; sea sickness). MSD Manuals – Adedamola A. Ogunniyi , MD, Harbor-UCLA Medical Center [reviewed May 2021; accessed Dec. 2022] Available from: https://www.msdmanuals.com/es-es/hogar/traumatismos-y-envenenamientos/cinetosis/cinetosis
[4] Study uncovers genetics of motion sickness – The News Courier [published Feb. 2015; accessed Dec. 2022] Available at: https://news-courier.com/neuroscience/news/study-uncovers-genetics-motion-sickness-282914
