Motion Sickness

What is motion sickness?

Motion sickness^[1] goes by many different names: airsickness, car sickness, rider’s vertigo, seasickness. No matter what it’s called, motion sickness is an umbrella term that describes the nausea, vomiting, and general discomfort that some people experience during transportation or motion (particularly while riding in a moving vehicle).Some people experience “air sickness” while on a plane. Others may have trouble riding roller coasters, skiing, or even playing video games (especially virtual reality) due to motion sickness. Dealing with mild motion sickness may just mean avoiding activities like reading or using a tablet while riding in a car. For those that experience severe motion sickness, however, riding on a boat or a plane can become a miserable experience. Whatever the case, motion sickness can make traveling and enjoying certain experiences difficult. While it’s not a life-threatening phenomenon, motion sickness can be incredibly uncomfortable. Often beginning with a feeling of uneasiness, it often progresses to dizziness, sweating, nausea, and even vomiting. Not everyone experiences motion sickness in the same way. Some people become woozy or develop a headache, while others may feel restless or feel the need to hyperventilate. Motion sickness most likely arises from “confusion” in the mechanism responsible for our sense of balance. Normally, our bodies are calibrated to anticipate no movement; everything should be flat and still. Let’s say, however, that you’re on a boat in choppy water. You see your world rock from side to side in front of you, even though you’re sitting still. While your body has an idea of what should be happening (you’re sitting still, and, therefore, not moving), your sensory input (what you’re feeling and seeing) is completely different. It’s when this kind of mixup in sensory input^[2] occurs that the body sometimes responds with motion sickness. In short, motion sickness occurs when the sensations you’re experiencing don’t agree with your anticipated reality, causing you to feel unwell. Thankfully, there is a myriad of ways to prevent or alleviate motion sickness. These range from avoiding certain foods that can trigger or worsen motion sickness to using medications and patches that can help you fight motion sickness before it arises.

How common is motion sickness?

If you’ve experienced motion sickness before, you’re not alone. Almost all people experience motion sickness to some degree. However, everyone has a different tolerance level of certain types of travel or experiences before experiencing motion sickness. This tolerance threshold also isn’t static: the severity of your motion sickness can change over time or based on what you eat and drink on a given day. Some people, for example, find that minimizing alcohol consumption can help reduce their motion sickness. Your body may also get used to certain types of motion: for example, your motion sickness might improve while riding on a cruise ship over the course of a week. Circumstances aside, some people are more susceptible to motion sickness than others. Generally speaking, about one in three^[3] people is highly susceptible to motion sickness. Children are also more prone to getting motion sickness than adults, and women experience motion sickness more often than men (especially when pregnant or menstruating). Ethnicity may even play a role in motion sickness: some evidence shows that people of Asian heritage are more likely to experience motion sickness than people of European descent.

What causes motion sickness?

Everyone can experience at least some degree of motion sickness. While some people may experience it much more severely than others, the cause of motion sickness is the same for everyone. Motion sickness arises due to what’s known as sensory conflict^[4], which arises when your senses aren’t aligned with how the world is moving around you. More specifically, sensory conflict occurs when the organs responsible for balance and equilibrium (those found in the inner ear^[5], heart and blood vessels, and nerves) detect movement, even when you’re not moving your body. Our senses of balance and equilibrium also rely on feedback from multiple body systems^[6]—including your eyes (vision), muscles, bones, and joints—to function properly. Consider the mixing of messages that can happen when you experience turbulence on an airplane. While your body senses the shifts in motion, you can’t actually see the movement taking place. This causes the disparity between what you feel and what you see that causes motion sickness. Activities like reading or using a tablet while riding in a car can cause motion sickness for the same reason. Despite the fact that your body is sensing motion, your eyes are focused on a static page or screen. Because of this, taking a break and looking out the window while riding in a car (which helps reconcile what you’re seeing with what you’re feeling) can help this form of motion sickness to pass. While the exact cause of the unpleasant feelings characteristic of motion sickness is unknown, researchers believe that they might be the body’s natural response to indicate that something is wrong with your senses.

Risk factors for motion sickness

It’s not entirely clear why age, gender, and ethnicity play a role in a person’s likelihood of experiencing motion sickness. It is known, however, that people with certain conditions are more likely to experience motion sickness than others. Motion sickness is thought to be a genetic condition^[7], albeit not a simple one. It is known as a “polygenic” condition. This means that motion sickness likely isn’t caused by one single gene, but rather results from the interaction of multiple different genes. That said, there have not yet been many studies into the genetic factors behind motion sickness. One of the studies⁷ that have been conducted found that motion sickness may develop as the result of roughly 35 genes acting together to produce the condition, many of which are linked to inner ear development (especially the otoliths, which help with balance and equilibrium) and visual development. The same study also found links between motion sickness and nerve interactions and insulin production. While motion sickness does run in families, no inherent hereditary pattern has been found. Ultimately, if you have a first-degree relative who gets carsick easily, you may be more likely to get carsick, as well. Women are also more susceptible to motion sickness than men, and children are more susceptible than adults. Some studies show that people of Asian descent are more susceptible than those of European descent. People who tend to get migraines—especially vestibular migraines—are more likely to experience motion sickness than those who aren’t, as are those who have had a traumatic brain injury (TBI) in the past.

Motion sickness symptoms

Motion sickness manifests itself in different ways in different people. However, some common signs and symptoms of motion sickness include^[8]:

• Dizziness
• Sweating
• Nausea
• Vomiting
• Cold sweats
• Headache
• Malaise
• Drowsiness
• Irritability
• Hyperventilation

The symptoms of motion sickness can range from mild to severe. For some people, motion sickness is brief and intermittent. Others may experience it for the entire duration of their trip. In some cases, symptoms can continue for a few hours or even a few days after^[9] you’ve completed your journey. If your symptoms persist for longer than this, you should contact your healthcare provider. It’s important to note that motion sickness usually occurs when you’re in a vehicle or situation that either creates or simulates motion. For example, motion sickness most commonly occurs when:

• Driving in a car
• Riding on a train
• Riding on a boat
• Flying in an airplane
• Riding a roller coaster
• Skiing
• Playing video games (especially virtual reality)

Experiencing the symptoms of motion sickness outside of these situations may be a sign of another more serious condition altogether. In this case, contact your healthcare provider immediately.

Complications from motion sickness

Typically, the only complication that can arise from motion sickness is dehydration^[10], which may occur if you experience frequent vomiting. It’s important that you stay hydrated if you get motion sickness. If vomiting persists, seek emergency medical treatment in order to prevent or treat dehydration.