To understand motion sickness, we need to understand what normally happens in our bodies every day. Specifically, we need to understand the interaction between our vision, the vestibular system, and our body position.

• Vision: This is the input from your eyes. As you look out into the world you'll see the world around you.
• Vestibular System: Big word, but really simple. This is your inner ear. An amazing work of creation that serves to keep you upright and balanced. You thank your vestibular system every day when you can walk in a straight line to the bathroom.
• Body Position: This is your hands and feet. As your hands and feet move they signal to your brain that they are doing so.

Your vision and body position seems like easy concepts to understand but your vestibular system may not. Here's a cool video describing what it does and how it works:

What is Your Vestibular System, and What does it Control?

When working normally, our eyes see the world around us, and we can react to changing environments. As we walk down the sidewalk, our vestibular system keeps us upright and walking smoothly. Finally, our brain can validate these signals by also getting inputs from our hands and feet. Together, all the inputs match what is expected by our brains.

To break it down in medical terms. The inner ear controls your body’s balance via the vestibular system. When the three pairs of semicircular canals, saccule, and utricle receive stimuli, they send signals to your brain.

However, at the same time, your eyes are registering movement. If these signals aren’t the same as what your inner ear is sending, then you’ll begin to feel the effects of motion sickness via two different signals being processed.

When Does Motion Sickness Occur?

Motion sickness occurs then when these signals fail to match up. For example, if you're reading in the car, your eyes will see a stationary book, but your vestibular system indicates movements. This makes your brain question reality, and it doesn't know what to do.

The symptoms of motion sickness will continue until our brain can learn what the new normal is. This is why sailors may get sick for the first several days of a boat trip, then be fine while at sea, but get sick again upon arriving back to the dock. The brain is constantly trying to interpret what normal is. The faster your brain learns, the faster you feel better.

The inner ear canal is what helps keep your body’s sense of balance. When the inner ear registers different signals to your brain from what your eyes are seeing, your body can be thrown off balance. This leads to some of the many symptoms of car sickness.

What Makes Motion Sickness Worse?

Evidence supports that everyone in a varying threshold can have some susceptibility to experiencing motion sickness. Some groups of people are prone to feeling stronger symptoms, but everyone can get it for the most part.

However, recent studies have narrowed down groups based on their age, genetics, and other outlining factors:

• Children Are More Prone to Experiencing Motion Sickness (2): Children between the ages of 2 and 15 tend to experience motion sickness more so than their adult counterparts—one speculation is that humans are habitual. Meaning, as we age, we tend to get reduced symptoms upon repeated exposure. A child who repeatedly experiences motion sickness may eventually have less severe symptoms when they are older.
• Women Are Known to Experience Stronger Motion Sickness (3): Females are also more susceptible to motion sickness. One reason for this is that women have spikes in estrogen levels. These increased levels lead to increased symptoms of motion sickness, such as nausea.
• Genetics Dictate Who Experiences Motion Sickness: If your ancestors have experienced severe motion sickness, then there is a high probability that you will too. A recent study (4) found a 55-70% chance that you’ll inherit your parent’s motion sickness tolerance. Hence, it’s a good idea to look at your medical history if you have frequent motion sickness.
• Medications Can Cause Motion Sickness (5): Medications can also have a heavy influence on whether you experience severe motion sickness symptoms. Some medications such as NSAIDs, antibiotics, or even birth control pills have increased motion sickness’s likeliness.
• Illnesses Can Aggravate Motion Sickness Symptoms (6): Other illnesses such as sinus congestion, ear infections, or concussions may also make you more prone to motion sickness. There have also been links to people who suffer from frequent migraines tend to be more likely to experience motion sickness.
• Migraines: People who suffer from migraine headaches are more likely to have symptoms from traveling (11).
• Hormonal: Pregnancy and menstrual cycles can increase susceptibility (12).
• Expectations: When you think you're going to get sick, you're more likely to get sick. This study told patients they were not likely to get sick and less of them actually became sick (13).

Motion Sickness in Kids

Motion sickness seems to be a learned trait. It's interestingly not found in children under the age of two, but studies show it peaks about age 9 (9). The theory shows that the body of children is still trying to figure out how to handle the sensory discrepancies found when traveling. As you get older, the likelihood of this happening actually decreases.

Kids are More Susceptible to Motion Sickness...Bummer

Like in adults, motion sickness in kids occurs when the brain receives conflicting signals from the eyes, ears, and nerves. Multiple senses are being sent at once, and they aren't aligning with each other. For example, on a long car ride, your child may be sitting in the back seat playing video games. Your child may hear cars passing by, but they can't see the vehicles and can only sense the car is moving. This will likely result in motion sickness.

Unlike adult motion sickness, children's motion sickness occurs because their bodies aren't used to it. Since motion sickness peaks at the age of nine, you're less likely to be affected by motion sickness as you get older. This isn't to say you'll stop having symptoms, but it'll likely not affect you as much.

However, a child hasn't fully experienced motion sickness enough times for their body to register what is occurring. As children move into adolescence, they may experience fewer symptoms due to repeated exposure. However, this progress varies from child to child.

As mentioned, kids are more likely to experience seasickness. The biggest cause is not enough exposure, and their bodies haven't learned what to do yet. The second reason is due to a child's developmental stage and growing body. Since their vestibular system isn't completely matured, this could play a significant role in why they are more susceptible to motion sickness.

Hence, their motion sickness is often very intense, and they can have a whole host of symptoms. Many children find that when they are motion sick, they feel dizzy, lightheaded, and often upset stomach. Very young children under the age of 5 may also experience irritated bowel movements or constipation.

Give kids a break in these situations and ensure you've planned ahead. Read below for tips on how to combat motion sickness in your kids.