Did you know the word "nausea" comes from the Greek root word naus, meaning "ship?" That may not be surprising, given the prevalence of motion sickness triggered when on the water. While anyone can experience motion sickness when travelling by boat, plane, train, bus, or car, some people are more prone to it than others. A number of factors could play a role in this queasiness, but it’s also, at least in part, affected by your genetics.

Whether or not you're the kind of person who worries about motion sickness during travel, you may have your genes to thank. With AncestryDNA + Traits, you can learn whether you have the genetic markers associated with motion sickness.

What Is Motion Sickness?

Motion sickness always occurs the same way, whether in the form of car sickness or sea sickness. It’s caused by your brain receiving mixed messages about your body’s movement.

Your inner ears’ fluid-filled canals play a key role. As you move, the fluid alerts the tiny hair cells in your ear to tell your body where your head is, based on gravity and motion. So, when riding in a car or a boat, for example, your inner ear reacts to the related movement.

Your eyes also register movement around you. However, when the nerve endings in your body sense you're not moving, but your eyes say you are, your brain doesn’t know how to handle this conflicting information. Anything that confuses your senses can cause motion sickness. Even amusement park rides, video games, or virtual reality games can trigger it.

Motion sickness feels like having a stomach bug, but it doesn't always cause the same symptoms. Common motion sickness symptoms include:

• Nausea and vomiting
• Cold sweats
• Headache
• Fatigue
• Irritability
• Rapid breathing
• Excessive salivation

Need to know how to get rid of motion sickness? These tips can help avoid or alleviate the symptoms:

• Roll your window down in a car for fresh air.
• Recline your seat back if possible and keep your eyes closed.
• Sip ginger tea or ginger ale for nausea.
• Take over-the-counter antihistamines or apply a scopolamine skin patch before travelling, but avoid antihistamines when operating a vehicle, as they can cause drowsiness.
• Using acupressure wristbands or bracelets.

Genetics and Motion Sickness

Determined to identify how much genetics affects motion sickness, the AncestryDNA team asked over 611,000 people, “Do you ever get motion sick?” By comparing respondents' answers to their DNA profiles, the team identified over 450 genetic markers genetic markers related to motion sickness.

Based on these findings, the team calculated a polygenic risk score, a statistical tool used to determine how likely you are to have a trait based on your genetics. In fact, motion-sickness is influenced considerably by genetics—over 10% of the difference in whether people experience motion-sickness can be explained by differences in their genetics. The rest is influenced by environmental factors, like what mode of transportation they use to travel.

While there isn’t a simple pattern of inheritance for motion-sickness—probably because it involves so many genetic markers—evidence does point to it passing through families. Those with a first-degree relative who experiences motion sickness have a higher chance of experiencing it themselves than the general public.

What Else Does Science Say About Motion Sickness?

Nearly anyone can experience motion sickness in certain environmental conditions. However, not everyone is particularly prone to developing it. According to one study, approximately 45.6% of all car users experienced motion sickness at least once in five years. When adjusted to only consider passengers, that number increased slightly to 46.3%, implying drivers tend to be marginally less susceptible to symptoms.

Further, the mode of transportation affects the likelihood of motion sickness. Those travelling by boat tend to experience motion sickness at higher rates than those travelling by car, and those on trains tend to experience it less.

Other factors that make someone more susceptible to motion sickness can include:

• A person’s age: Motion sickness is most common between the ages of 6 and 9, declining through the teenage years as people adjust to frequent motion. Older adults tend to be the least susceptible to developing symptoms.
• Hormonal fluctuations: These changes, common during pregnancy or at certain stages of the menstrual cycle, may also increase a person's proneness to motion sickness.
• Certain activities: Reading a book or a map while in a moving vehicle might trigger symptoms. This is because those activities can worsen the disconnect between what you see and feel—your eyes perceive the text as stationary, yet your body still detects movement around you.
• Strong smells: These can make symptoms like nausea worse and harder to handle.

Interesting Facts About Motion Sickness

Ginger tends to ease motion sickness, thanks to its calming effects on the gastrointestinal tract. It's associated with a reduction in rates of vomiting and cold sweats, but it doesn't necessarily ease feelings of nausea in everyone.

Typically, motion sickness symptoms subside within four hours after stopping motion. In some cases, they may linger for up to a few days. Though rare, some people experience motion sickness long after they stop moving. The condition, known as “sickness of disembarkation,” is typically associated with long treks on the ocean, but planes, trains, and cars can cause it too. Some people can experience this even when using virtual reality devices or sitting on a waterbed.

Ready to discover the genetic story behind sensory traits like motion sickness, sun sneezing, fresh coriander aversion, and more? Take an AncestryDNA + Traits test today and learn how your genetics contribute to and influence who you are. If you've already taken a test, log in with your Ancestry subscription to view your results.