Motion sickness is a common problem in people traveling by car, train, airplanes, and especially boats. Anyone can get it, but it is more common in children, pregnant women, and people taking certain medicines. Motion sickness can start suddenly, with a queasy feeling and cold sweats. It can then lead to dizziness and nausea and vomiting.

Your brain senses movement by getting signals from your inner ears, eyes, muscles, and joints. When it gets signals that do not match, you can get motion sickness. For example, if you are reading on your phone while riding a bus, your eyes are focused on something that is not moving, but your inner ear senses motion.

Where you sit can make a difference. The front seat of a car, forward cars of a train, upper deck on a boat or wing seats in a plane may give you a smoother ride. Looking out into the distance - instead of trying to read or look at something in the vehicle - can also help.

Motion sickness is a common condition characterized by a feeling of unwellness brought on by certain kinds of movement. The usual symptoms include dizziness, pale skin (pallor), and sweating, followed by nausea and vomiting. Affected individuals may also experience rapid breathing (hyperventilation), headache, restlessness, and drowsiness. These symptoms can be triggered by many kinds of motion, particularly traveling in a car, bus, train, airplane, or boat. Amusement park rides, skiing, and virtual reality environments can also induce motion sickness.

Motion sickness is very common. About 1 in 3 people are considered highly susceptible to motion sickness. However, almost everyone will become motion sick if exposed to motion that is intense enough.

Motion sickness is more common in some groups of people than in others, for reasons that are not fully understood. The condition is more common in women (particularly during menstruation or pregnancy) than in men, and more common in children than in adults. People who have migraine headaches, including a balance disorder called vestibular migraine, have a higher risk of motion sickness than those who do not have these conditions. People in some ethnic and geographic groups are more likely to report being susceptible to motion sickness; for example, studies suggest that there is a higher prevalence of motion sickness among Asians than among Europeans.

Motion sickness happens when the movement you see is different from what your inner ear senses. This can cause dizziness, nausea, and vomiting. You can get motion sick in a car, or on a train, airplane, boat, or amusement park ride. Motion sickness can make traveling unpleasant, but there are strategies to prevent and treat it.

Preventing motion sickness without medicine

Avoiding situations that cause motion sickness is the best way to prevent it, but that is not always possible when you are traveling. The following strategies can help you avoid or lessen motion sickness.

• Sit in the front of a car or bus.
• Choose a window seat on flights and trains.
• If possible, try lying down, shutting your eyes, sleeping, or looking at the horizon.
• Stay hydrated by drinking water. Limit alcoholic and caffeinated beverages.
• Eat small amounts of food frequently.
• Avoid smoking. Even stopping for a short period of time helps.
• Try and distract yourself with activities, such as listening to music.
• Use flavored lozenges, such as ginger candy.

Using medicines for motion sickness

Medicines can be used to prevent or treat motion sickness, although many of them cause drowsiness. Talk to a healthcare professional to decide if you should take medicines for motion sickness. Commonly used medicines are diphenhydramine (Benadryl), dimenhydrinate (Dramamine), and scopolamine.

Special Consideration for Children

Motion sickness is more common in children ages 2 to 12 years old.

Some medicines used to prevent or treat motion sickness are not recommended for children. Talk to your healthcare professional about medicines and correct dosing of medicines for motion sickness for children. Only give the recommended dosage.

Although motion sickness medicines can make people sleepy, it can have the opposite effect for some children, causing them to be very active. Ask your doctor if you should give your child a test dose before traveling.

Motion sickness is the term attributed to physiologic responses to motion by sea, car, train, air, and virtual reality immersion. Given sufficient stimulus all people with functional vestibular systems can develop motion sickness. However, people vary in their susceptibility. Risk factors include the following:

• Age—children aged 2–12 years are especially susceptible, but infants and toddlers are generally immune. Adults older than 50 years are less susceptible to motion sickness.
• Sex—women are more likely to have motion sickness, especially when pregnant, menstruating, or on hormones.
• Race/ethnicity—Asians may be more susceptible to motion sickness than Europeans.
• Migraines—people who get migraine headaches are more prone to motion sickness, especially during a migraine.
• Medication—some prescriptions can worsen the nausea of motion sickness.

The factors that contribute to motion sickness are not well understood, but susceptibility to the condition does seem to be partly genetic. When motion sickness occurs, it likely results from a mismatch in signals about movement coming from different parts of the body. The brain senses movement by combining signals from the inner ears, eyes, muscles, and joints. When the eyes signal to the brain that the body is still (for example, a moving car appears stationary to the person riding in it), but the inner ears and other parts of the body signal that the body is in motion, a conflict occurs. Researchers believe it is this sensory conflict that triggers the symptoms of motion sickness. The mechanism by which a sensory mismatch could lead to dizziness, nausea, and related symptoms is unclear, and other explanations for motion sickness are also being explored.

Common, complex conditions such as motion sickness are often polygenic, which means they involve variations in many genes. However, little is known about the specific genes involved in motion sickness because few studies have been done to identify them.

One study compared genetic variations in a large number of people with and without a susceptibility to motion sickness. The researchers found common genetic variations in or near 35 genes that may be associated with the condition. These genes play a wide variety of roles in the body: some are involved in eye and ear development, and others in the formation of otoliths, which are tiny structures in the inner ear that are involved in sensing gravity and movement. Still other identified genes play roles in the development and function of junctions between nerve cells (synapses) where cell-to-cell communication takes place, and in the way the body processes the simple sugar glucose and the hormone insulin, which helps regulate blood glucose levels. Additional research will be necessary to confirm the association between variations in specific genes and motion sickness susceptibility.

Seasickness results from a conflict in the inner ear and the erratic motion of a vessel.

One of the least pleasant aspects of going to sea is the possibility of getting seasick. An individual's susceptibility to seasickness is highly variable. If you've ever had motion sickness when traveling by car, plane, or amusement park ride, you may be more susceptible to seasickness while aboard a vessel.

Seasickness is a result of a conflict in the inner ear, where the human balance mechanism resides, and is caused by a vessel’s erratic motion on the water. Inside the cabin of a rocking boat, for example, the inner ear detects changes in both up-and-down and side-to-side acceleration as one’s body bobs along with the boat. But, since the cabin moves with the passenger, one’s eyes register a relatively stable scene. Agitated by this perceptual incongruity, the brain responds with a cascade of stress-related hormones that can ultimately lead to nausea, vomiting, and vertigo.

Additionally, an affected person’s symptoms can be magnified by the strong odors of things like diesel fumes and fish. Seasickness usually occurs in the first 12 to 24 hours after “setting sail,” and dissipates once the body acclimates to the ship's motion. It’s rare for anyone to get or stay ill beyond the first couple of days at sea—unless the vessel encounters really rough waves.

If you do get seasick, take comfort in the fact that recovery is only a matter of time, and the survival rate is 100 percent! Sensible eating, good hydration, and some patience are all that are usually required to get past a bout of seasickness.

Here are a few tips to help ease the symptoms of seasickness:

• Maintain your fluid intake. Seasickness and related medications cause dehydration and headaches. Drink water, low-acidity juices like apple and carrot, or clear soup, and avoid milk and coffee.
• Keep moving. Most people find that being busy keeps their minds off their discomfort.
• Stay on deck, even if it’s raining, because the fresh air is often enough to speed recovery. The closed-in quarters below deck magnify the vessel’s motion and worsen symptoms.
• Carry a plastic bag. This simple approach allows for peace of mind by eliminating some of the panic of getting seasick. If you have to vomit "over the side,” though, check the direction of the wind and waves. Staying leeward (the side of the ship that’s sheltered from the wind) will ensure that an unpleasant experience doesn’t get even worse.
• Consider an over-the-counter medication to prevent or minimize motion sickness. A dose is usually recommended about an hour prior to setting sail, and as needed at sea. These medications tend to be dehydrating, though, so drink plenty of water.

And don’t be embarrassed for getting seasick. Many people do—including seasoned travelers, professional fishers, sailors, and marine scientists.

Motion sickness does not have a clear pattern of inheritance, although it does tend to cluster in families. People who have a first-degree relative (for example, a parent or sibling) who is highly susceptible to motion sickness are more likely than the general public to get motion sick themselves.

Travelers suffering from motion sickness commonly exhibit some or all of the following symptoms:

• Nausea
• Vomiting/retching
• Sweating
• Cold sweats
• Excessive salivation
• Apathy
• Hyperventilation
• Increased sensitivity to odors
• Loss of appetite
• Headache
• Drowsiness
• Warm sensation
• General discomfort

Antihistamines are the most frequently used and widely available medications for motion sickness; nonsedating ones appear to be less effective. Antihistamines commonly used for motion sickness include cyclizine, dimenhydrinate, meclizine, and promethazine (oral and suppository). Other common medications used to treat motion sickness are anticholinergics such as scopolamine (hyoscine—oral, intranasal, and transdermal), antidopaminergic drugs (such as prochlorperazine), metoclopramide, sympathomimetics, and benzodiazepines. Clinical trials have not shown that ondansetron, a drug commonly used as an antiemetic in cancer patients, is effective in the prevention of nausea associated with motion sickness.

Medications in Children

Although using antihistamines to treat motion sickness in children is considered off-label, for children aged 2–12 years, dimenhydrinate (Dramamine), 1–1.5 mg/kg per dose, or diphenhydramine (Benadryl), 0.5–1 mg/kg per dose up to 25 mg, can be given 1 hour before travel and every 6 hours during the trip. Because some children have paradoxical agitation with these medicines, a test dose should be given at home before departure. Oversedation of young children with antihistamines can be life-threatening.

Scopolamine can cause dangerous adverse effects in children and should not be used; prochlorperazine and metoclopramide should be used with caution in children.

Approximately 33 percent of people experience a mild problem with motion sickness, whereas up to 66 percent experience motion sickness under extreme conditions, such as being on a tossing boat with no view of the horizon. Connections between regions in the brain stem and the autonomic system result in the symptoms of nausea, cold sweats, and vomiting.

The part of the brain responsible for vomiting, or emesis, is known as the area postrema. It is located next to the fourth ventricle and is not restricted by the blood–brain barrier, which allows it to respond to chemicals in the bloodstream—namely, toxins that will stimulate emesis. There are significant connections between this area, the solitary nucleus, and the dorsal motor nucleus of the vagus nerve. These autonomic system and nuclei connections are associated with the symptoms of motion sickness.

Motion sickness is the result of conflicting information from the visual and vestibular systems. If motion is perceived by the visual system without the complementary vestibular stimuli, or through vestibular stimuli without visual confirmation, the brain stimulates emesis and the associated symptoms. The area postrema, by itself, appears to be able to stimulate emesis in response to toxins in the blood, but it is also connected to the autonomic system and can trigger a similar response to motion.

Autonomic drugs are used to combat motion sickness. Though it is often described as a dangerous and deadly drug, scopolamine is used to treat motion sickness. A popular treatment for motion sickness is the transdermal scopolamine patch. Scopolamine is one of the substances derived from the Atropa genus along with atropine. At higher doses, those substances are thought to be poisonous and can lead to an extreme sympathetic syndrome. However, the transdermal patch regulates the release of the drug, and the concentration is kept very low so that the dangers are avoided. For those who are concerned about using “The Most Dangerous Drug,” as some websites will call it, antihistamines such as dimenhydrinate (Dramamine®) can be used.

Complementary approaches marketed for preventing or treating motion sickness include acupressure, magnets, ginger, pyridoxine, and homeopathic remedies.

Acupressure and Magnets

Research does not support the use of acupressure or magnets for motion sickness.

Ginger

Although some studies have shown that ginger may ease pregnancy-related nausea and vomiting, there is no strong evidence that it helps with motion sickness.

Homeopathic Products

There is no evidence supporting claims that homeopathic products prevent or alleviate motions sickness.

Pyridoxine (Vitamin B₆)

Although an American College of Obstetricians and Gynecologists 2015 Practice Bulletin Summary recommends pyridoxine alone or in combination with doxylamine (an antihistamine) as a safe and effective treatment for nausea and vomiting associated with pregnancy, there is no evidence supporting claims that pyridoxine prevents or alleviates motion sickness.

Safety

• In some people, ginger can have mild side effects such as abdominal discomfort. Research has not definitely shown whether ginger interacts with medications, but concerns have been raised that it might interact with anticoagulants. The effect of using ginger supplements with common over-the-counter drugs for motion sickness is unknown.
• Taking excessive doses of pyridoxine supplements for long periods of time can affect nerve function.

Nonpharmacologic interventions to prevent or treat motion sickness include the following:

• Being aware of and avoiding situations that tend to trigger symptoms.
• Optimizing position to reduce motion or motion perception—for example, driving a vehicle instead of riding in it, sitting in the front seat of a car or bus, sitting over the wing of an aircraft, holding the head firmly against the back of the seat, and choosing a window seat on flights and trains.
• Reducing sensory input—lying prone, shutting eyes, sleeping, or looking at the horizon.
• Maintaining hydration by drinking water, eating small meals frequently, and limiting alcoholic and caffeinated beverages.
• Avoiding smoking—even short-term cessation reduces susceptibility to motion sickness.
• Adding distractions—controlling breathing, listening to music, or using aromatherapy scents such as mint or lavender. Flavored lozenges may also help.
• Using acupressure or magnets is advocated by some to prevent or treat nausea, although scientific data on efficacy of these interventions for preventing motion sickness are lacking.
• Gradually exposing oneself to continuous or repeated motion sickness triggers. Most people, in time, notice a reduction in motion sickness symptoms.