Motion sickness

Sometimes you feel sick in a car or boat. This happens when your eyes and ears disagree. Your ears feel the movement of the ride. But your eyes might see a still book. This mix-up makes your tummy feel bad. You might feel dizzy or tired. To feel better, try to look at the horizon. This helps your eyes see the motion too. Almost everyone feels this way at least once. It is a very common thing to happen.

Have you ever felt sick in a car or boat? This is called motion sickness. It happens when your brain gets mixed signals. Your inner ear helps with balance. We call this the vestibular system. It senses when your body moves. But your eyes might see something still. This might happen if you read a book in a car. Your ears feel the bumps, but your eyes see a still page. This conflict makes you feel unwell.

You might feel dizzy, tired, or nauseous. Some people even get a headache or cold sweat. Almost everyone feels this at least once. About one-third of people are more likely to feel it.

To feel better, try to look at the horizon. This helps your eyes see the motion too. You can also keep your head very still. Some people use medicine to help. There are many types of medicine for this. Some work by blocking certain signals in the body.

Motion sickness is a common feeling of being unwell. It happens when there is a difference between real motion and expected motion. Most people will feel this at least once in their lives. About one-third of the population is very sensitive to it. Women can sometimes be affected more easily than men. Common symptoms include nausea, vomiting, and dizziness. You might also feel a headache, tiredness, or a cold sweat.

This feeling occurs because of a conflict in the brain. Your inner ear has a vestibular system. This system helps you with balance and detects movement. Your eyes also tell your brain about motion through sight. If the signals from your ears and eyes do not match, you feel sick. For example, you might feel a car turn. However, your eyes might be looking at a still book. The eyes see stillness while the ears feel the turn.

People have noticed this since the time of Homer in the eighth century BC. In the early 1900s, a scientist named Róbert Bárány studied it. He was an Austro-Hungarian scientist who watched railroad passengers. He saw their eyes move back and forth as they looked at scenery. He called this railway nystagmus. He published his findings in a journal in November 1921.

There are many different types of motion sickness. Carsickness happens during car travel. Airsickness occurs on airplanes. Seasickness happens on boats, often from rocking motions. Space motion sickness occurs in zero gravity. This happened to the cosmonaut Gherman Titov in August 1961. He was on the Vostok 2 spacecraft. Later, astronauts like Frank Borman and Rusty Schweickart felt it too. Even watching large IMAX films can cause it.

There are ways to help the body feel better. You can try behavioral measures like keeping your head still. It also helps to focus on the horizon. Doctors can use different medications to treat it. Some are called antimuscarinics, like scopolamine. Others are H1 antihistamines, like dimenhydrinate. Some researchers even use virtual reality to help. They use it to show a stable horizon to the brain. This can help the brain match what it sees with what it feels.

Motion sickness is a physical condition caused by a mismatch between actual and expected motion. It occurs when the brain receives conflicting signals from different sensory systems. Most people will experience motion sickness at least once in their lives. However, susceptibility varies significantly across the human population. About one-third of people are considered highly susceptible to these sensations. Women may be more easily affected than men. Symptoms can range from nausea and vomiting to dizziness and headaches. Some people also experience cold sweats, tiredness, or increased salivation.

The primary mechanism behind this condition is a sensory conflict. The brain relies on the vestibular system to maintain balance and detect movement. This system is located in the inner ear and detects motion mechanically. At the same time, the visual system provides information through sight. When these two inputs do not correspond, the brain becomes confused. For example, if you read a book in a moving car, your eyes see a stationary object. However, your inner ear senses the turns and bumps of the vehicle. This contradiction between the eyes and the vestibular system triggers the sickness.

Scientists categorize motion sickness into three distinct types based on how motion is perceived. The first type is motion that is felt but not seen, known as terrestrial motion sickness. This includes carsickness, which often happens when passengers look at small screens or books. Airsickness is another terrestrial form caused by the tilting or banking of an airplane. Seasickness occurs on watercraft and is often triggered by regular rocking or rolling motions. The second type is motion that is seen but not felt, called visually induced motion sickness (VIMS). This can happen when watching large IMAX films or playing video games. The third type occurs when both systems detect motion, but the signals do not match.

History shows that humans have observed these symptoms for a very long time. Descriptions of motion sickness date back to the eighth century BC during the time of Homer. In the early 20th century, the Austro-Hungarian scientist Róbert Bárány conducted important research. He studied railroad passengers looking out of side windows at passing scenery. He observed that their eyes moved back and forth in a specific pattern. He named this phenomenon "railway nystagmus" or "optokinetic nystagmus." Bárány published these significant findings in the journal Laeger in November 1921.

Space travel introduced a unique and intense version of this condition. In zero gravity, the vestibular system's gravity-dependent operations are interrupted. This prevents the visual and vestibular systems from providing a unified sensory representation. Space motion sickness can be more intense because weightlessness is an unfamiliar state. The first recorded case was Soviet cosmonaut Gherman Titov in August 1961. He experienced dizziness and nausea while aboard the Vostok 2 spacecraft. Later, Apollo astronauts Frank Borman and Rusty Schweickart also faced severe symptoms. On the Apollo 9 mission, Rusty Schweickart's symptoms were so bad they required mission changes.

There are several ways to manage or treat the symptoms of motion sickness. Behavioral measures are often the first line of defense. These include keeping the head still and focusing your eyes on the horizon. Medical treatments involve different classes of drugs to target the body's response. Antimuscarinics, such as scopolamine, are one type of medication used. H1 antihistamines, such as dimenhydrinate, are another common option. Some doctors may also use amphetamines like dexamphetamine. However, side effects can sometimes limit how much these medications are used.

Modern technology is even being used to help solve the problem of motion sickness. Virtual reality (VR) can sometimes cause sickness due to system lagging or software crashes. However, researchers are finding ways to use VR as a therapeutic tool. By using a headset, they can simulate a stable artificial horizon for the user. This provides visual cues that align with the body's actual movement. This method helps the brain reestablish sensory integration between the eyes and the ears. Such systems have shown great promise in helping people reduce seasickness within minutes.