Motion sickness
At a Glance
Motion sickness is a common disturbance of the inner ear caused by repeated motion that results in nausea, dizziness, and vomiting due to conflicting sensory signals sent to the brain.
It is most common in children between the ages of 2 and 12 and frequently affects pregnant women, though approximately one in three people is considered highly susceptible to the condition.
Motion sickness is an acute condition that is highly treatable and manageable, typically resolving rapidly once the triggering movement ceases.
The outlook is generally excellent as the condition causes no long-term damage and often improves as children grow older, although some individuals remain susceptible throughout adulthood.
How It Affects You
Motion sickness creates a physiological stress response throughout the body when the brain receives conflicting signals from the eyes, inner ears, and sensory nerves in the muscles and joints. This sensory mismatch primarily disrupts the digestive system and the vestibular system, which controls balance, leading to a general sense of malaise and physical discomfort. The effects are typically temporary and subside once the motion stops or the body adapts.
- Severe nausea, vomiting, and loss of appetite
- Dizziness, vertigo, and headache
- Cold sweats, pale skin, and fatigue
Causes and Risk Factors
Underlying Causes
The primary cause of motion sickness is a conflict between the senses, known as sensory conflict theory. The brain receives mismatched information from the three systems that sense motion: the eyes (visual system), the inner ear (vestibular system), and the nerves in the muscles and joints (proprioception). For example, if you are reading in a moving car, your eyes signal that you are stationary, but your inner ear senses the movement of the vehicle. This discrepancy confuses the brain, triggering a stress response that releases neurotransmitters leading to nausea and other symptoms.
Risk Factors and Triggers
Certain individuals are more prone to motion sickness than others due to biological and environmental factors. Genetics play a significant role, as susceptibility tends to run in families. Women are more likely to experience symptoms than men, particularly during menstruation or pregnancy, likely due to hormonal fluctuations. People who suffer from migraines, especially vestibular migraines, are at a significantly higher risk. Common triggers include riding in cars, boats, airplanes, or trains, as well as amusement park rides and virtual reality experiences.
Prevention Strategies
Prevention focuses on reducing sensory conflict before it starts. Primary prevention involves choosing the seat with the least motion, such as the front seat of a car, the forward cabin of a train, or the wing section of an airplane. Looking at a fixed point on the horizon helps synchronize visual and vestibular signals. Avoiding heavy meals, alcohol, and strong odors before travel can also reduce the likelihood of symptoms. For those with high susceptibility, taking preventive medications like antihistamines or applying a scopolamine patch before travel is often effective.
Diagnosis, Signs, and Symptoms
Clinically Meaningful Symptoms
Symptoms of motion sickness typically follow a consistent progression. The earliest signs often include a sudden sense of uneasiness, yawning, and fatigue. This is frequently followed by the onset of cold sweats, pale skin (pallor), and increased saliva production. As the condition progresses, the primary symptom becomes nausea, which can lead to vomiting and dry heaving if the motion continues. Some individuals may also experience headaches, difficulty concentrating, and rapid breathing.
Diagnosis
Clinicians identify motion sickness primarily through a review of the patient's medical history and a description of their symptoms in relation to movement. There are no specific laboratory tests or imaging scans required to diagnose the condition. The doctor will ask questions about when symptoms occur, how long they last, and what specific types of travel trigger them.
Differential Diagnosis
While usually straightforward, motion sickness can sometimes be confused with other conditions that cause nausea or dizziness. It is important to distinguish it from viral gastroenteritis (stomach flu), which typically presents with fever or diarrhea not related to motion. It must also be differentiated from vestibular disorders like vertigo or Ménière's disease, where dizziness occurs even when the body is stationary.
Treatment and Management
Medications
Several medications are effective for preventing and treating motion sickness. Over-the-counter antihistamines, such as dimenhydrinate and meclizine, are commonly used to block the brain signals that cause nausea, though they may cause drowsiness. For longer trips, doctors may prescribe a scopolamine patch, which is applied behind the ear several hours before travel and provides protection for up to three days. These treatments are most effective when taken before symptoms begin rather than after they have started.
Lifestyle and Self-Care Strategies
Non-medical strategies can significantly manage symptoms. Focusing your eyes on the horizon or a distant, stationary object can help realign your sensory perception. improving ventilation by opening a window or directing air vents toward your face can also provide relief. Many people find relief using ginger, available in candies, teas, or supplements, which can help settle the stomach without causing drowsiness. Acupressure wristbands that target the P6 pressure point on the wrist are another option for symptom management.
When to See a Doctor
Most cases of motion sickness resolve on their own and do not require professional care. However, you should see a doctor if you experience intractable vomiting that leads to signs of dehydration, such as dry mouth, dark urine, or extreme weakness. Medical attention is also warranted if you develop motion sickness symptoms at times when you are not moving, or if the symptoms persist for days after the travel has ended, as this could indicate an underlying inner ear or neurological disorder.
Severity and Prognosis
Severity and Course
Motion sickness ranges from mild discomfort to severe incapacitation. For most people, it is a self-limiting condition, meaning it resolves on its own once the triggering motion stops or the person exits the vehicle. Symptoms typically disappear within 15 to 30 minutes after the motion ends. In some cases, the body adapts to the motion over time, a process known as habituation, which explains why sailors often get their "sea legs" after a few days at sea.
Possible Complications
The primary complication of severe motion sickness is dehydration and electrolyte imbalance caused by excessive vomiting. This is particularly concerning for young children, pregnant women, and older adults. In rare cases, the physical strain of violent retching can cause minor tears in the esophagus, known as Mallory-Weiss tears. Chronic anxiety about travel (anticipatory anxiety) can also develop, leading people to avoid necessary or enjoyable activities.
Prognosis
The long-term prognosis for motion sickness is very good. It does not shorten life expectancy or cause permanent organ damage. Many children eventually outgrow the condition or experience a significant reduction in symptom severity as they reach adulthood. With appropriate planning and management strategies, most individuals can travel comfortably and maintain a normal quality of life.
Impact on Daily Life
Impact on Activities
Motion sickness can restrict travel options, making long car rides, cruises, or flights difficult. This may limit vacation choices, job opportunities that require frequent travel, or participation in school field trips. Adults may find themselves unable to read or work on laptops while commuting, reducing productivity. In social settings, individuals might avoid amusement parks, boating trips, or 3D movies to prevent embarrassment or illness.
Coping Strategies
Practical coping involves planning ahead. This includes offering to drive the vehicle, as drivers rarely get motion sick due to their ability to predict motion. Scheduling trips during times when traffic is light, taking frequent breaks to walk around, and keeping the travel environment cool and free of strong smells can help. Listening to music or audiobooks serves as a good distraction without requiring visual focus that triggers symptoms.
Questions to Ask Your Healthcare Provider
Patients should be prepared to discuss their specific triggers and history. Helpful questions to ask include:
- What is the best medication for me given my age and other health conditions?
- Are there non-drowsy alternatives that I can take for short trips?
- How far in advance should I take medication for it to be effective?
- Is it safe to use ginger supplements or wristbands alongside prescription medications?
- Could my symptoms be a sign of a different balance disorder?
Common Questions and Answers
Q: Why do I get motion sick but the person next to me does not?
A: Susceptibility varies widely among individuals due to genetics, age, and biological differences in how the brain processes sensory information. Some people have a lower threshold for sensory conflict, meaning their brains react more quickly to mismatched signals from the eyes and inner ears.
Q: Can I get motion sickness from playing video games?
A: Yes, this is often called "simulator sickness" or "cybersickness." It occurs because your eyes see motion on the screen, but your body feels that you are sitting still, creating the same type of sensory conflict that causes traditional motion sickness.
Q: Will I eventually grow out of motion sickness?
A: Many people do see an improvement in symptoms as they age, particularly after adolescence. While some adults remain susceptible, repeated exposure to the trigger often helps the brain adapt, reducing the severity of the reaction over time.
Q: Does ginger really work for motion sickness?
A: Yes, many studies and anecdotal reports suggest that ginger can be effective in reducing nausea associated with motion sickness. It is considered a safe, natural remedy that works by settling the stomach and does not cause the drowsiness associated with some pharmaceutical treatments.
Q: Is it okay to read or look at my phone while riding in a car?
A: It is generally not recommended if you are prone to motion sickness. Reading or looking at a screen focuses your vision on a stationary object, which conflicts with the motion your inner ear senses, thereby increasing the likelihood of nausea.