Some people feel very sick while travelling in an airplane, boat, train, or car. They may feel queasy or nauseous or may vomit, and they may have a headache. This condition is called motion sickness.
Children are more susceptible to motion sickness than adults. More than half of children experience motion sickness when travelling by car ("carsickness"). Motion sickness is most commonly experienced when travelling by ship, with estimations that up to 100% of travellers experience "seasickness."
Motion sickness is rare in those under 2 years of age, but is most common between ages 3 and 12. Women experience motion sickness more than men. It also occurs more often in women during menstrual cycles and pregnancy.
When you are in a vehicle that moves continuously with relatively slow and prolonged motion, the organ of balance in your inner ear may be affected, causing motion sickness. Motion sickness is likely to happen if you are also worried about having an attack, if the air is stuffy or filled with fumes, or if you have just eaten a big meal. Looking at food can make motion sickness worse.
In motion sickness, a discrepancy exists between the motion that is expected to occur and the actual motion sensed by the organ of balance in the inner ear. These unexpected signals translate into a confused message by the brain, leading to the development of symptoms.
Generally, symptoms disappear once the brain adapts to the new pattern of motion. Two neurotransmitters (chemicals that relay messages to cells within the brain) - acetylcholine and dopamine - are thought to play an important role in causing motion sickness.
Symptoms and Complications
Mild motion sickness may cause a headache and make someone feel a little uncomfortable with mild nausea. Other symptoms include dizziness, fatigue, and weakness. In severe cases, you may become very anxious, sweat or salivate a lot, become pale and nauseous, and start to vomit.
Symptoms of motion sickness usually go away after the motion has stopped but may take up to 3 days to completely resolve. There are no serious complications of motion sickness to worry about, unless vomiting continues to the point where you become dehydrated.
Making the Diagnosis
A diagnosis of motion sickness is made by observing the symptoms and signs and determining that they occur only while you are "in motion."
Treatment and Prevention
There are several medications available to manage motion sickness. These medications are available in various forms, including oral tablets, rectal suppositories, and transdermal patches.
Antihistamines such as dimenhydrinate* and diphenhydramine are available in pharmacies without a prescription. They work best when they are taken 30 minutes to an hour before a journey. Some medications such as meclizine or scopolamine are longer-acting than others and work best for longer journeys. Scopolamine is a patch that should be applied 12 hours before travelling.
Since antihistamine medications that are used for motion sickness tend to cause drowsiness, it is best not to drive a vehicle, operate machinery, or do anything that requires full concentration when taking them. It is important not to take antihistamine medications with alcohol, sleeping medications, or tranquilizers unless instructed to do so by your doctor. A few people may experience side effects such as blurred vision, headache, or stomach ache from taking antihistamines. A small number of people may have trouble urinating and may have palpitations (abnormal heartbeat). If this occurs, contact your doctor.
There is an increased chance of side effects when combining antihistamines with other medications or alcohol in seniors. Motion sickness medications should never be given to babies and very young children. They can become agitated and could possibly experience a life-threatening convulsion if given too much of the medication.
Ask your doctor for advice before taking motion sickness medications, especially if you're feeling constipated, are pregnant, have a history of heart rhythm problems, or have a stomach ulcer, narrow angle glaucoma, or an enlarged prostate.
Non-medicinal ways to reduce motion sickness include sitting where there is the least motion. For example, sitting over the wings in airplanes or in the front seat of a car (except children) or in the central location of a boat can help. A semi-reclined position with the head braced is best. Reading should be avoided.
People who suffer from motion sickness should avoid the following before or during travel:
- dairy products
- foods high in salt, protein, or calories
- large meals
- unpleasant odours
If you read or look at nearby objects, or look at things going by such as the scenery in your trip, motion sickness could get worse. It is better to focus on objects on the horizon.
Other treatments such as wristbands and magnets may be helpful, but there is little information available about their effectiveness.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.