What is Motion Sickness?
Have you ever felt dizzy on a car or train ride? This sensation of wooziness is called motion sickness. This usually occurs when you’re in repeated motion in a vehicle or any other movement that can affect your inner ear and balance.
Repeated motion tends to mess up the balance of the body. The sensory organs receive different signals. For example, when you’re in an airplane, your body may feel the minor turbulences, but your eyes see a stationary view, and this is conflicting. The different sensory receptors send mixed signals to the brain, and this causes motion sickness.
Humans have a functional vestibular system that is responsible for the balance. The sensory systems in your body include the inner ear, eyes, skin pressure receptors, muscle and joint sensory receptors. The inner ear contains motion-sensing organs. It is an important contributing factor to motion sickness.
People with motion sickness can usually diagnose themselves when they travel or do other specific activities that involve a lot of movement. The symptoms wear off after the travel, usually. In rarely severe cases, professional help may be required.
Symptoms of Motion Sickness
Common symptoms of motion sickness include:
- Nausea
- Vomiting
- Stomach upset
- Dizziness
- Loss of balance
- Sweating
- Headache
- Drowsiness
The Genetics Behind Motion Sickness
Variations in certain genes have been observed in people with motion sickness. Studying these variations can help predict if a person has a higher risk of motion sickness compared to other people.
GPD2 Gene
The GPD2 gene encodes an enzyme involved in glucose homeostasis (maintenance of blood glucose levels). The enzyme is called glycerol-3-phosphate dehydrogenase 2.
rs56051278
rs56051278 is an SNP found in the GPD2 gene. The minor allele, the G allele, is found to be associated with an increased risk of motion sickness.
PRDM16 Gene
The PRDM16 gene encodes a protein called PR Domain containing 16. This protein is also called a zinc finger transcription factor. It is involved in the development of brown adipose tissue, also called brown fat. The main function of brown fat is to turn food into body heat.
rs61759167
rs61759167 is an SNP found in the PRDM16 gene. The minor allele, the T allele, is found to be associated with an increased risk of motion sickness.
Non-Genetic Factors that Influence Motion Sickness
- Travelling by road/air/water
- Any form of repeated motion like amusement rides
- Pregnant women are more likely to experience motion sickness.
- Young children, between the ages of 2 and 12, are also more likely to experience motion sickness.
How to Manage Motion Sickness?
Following the recommendations mentioned below, can help avoid motion sickness while travelling:
- In a car, try to open a window for some fresh air every once in a while.
- Avoid reading books during travel.
- Close your eyes and relax or try napping.
- Driving yourself or sitting in the front can help relieve symptoms.
- Get plenty of rest the night before traveling and eat a few hours ahead so that your stomach is settled.
- Avoid greasy, spicy, or acidic food before travel.
- Chewing fresh ginger or in a tablet form can help deal with symptoms.
- Chewing, in general, is found to help with conflicts between vision and balance. Chewing gum is a common way to deal with motion sickness symptoms.
- Peppermint has soothing effects on the body and helps you relax.
- Breathing exercises and acupuncture are found to help people.
Medications
If home remedies don’t help you deal with symptoms completely, certain medications can be taken. These are usually prescribed by a doctor. These medications include:
- Scopolamine: It is the most commonly prescribed medication. It is in the form of a patch that is placed behind the ear 6-8 hours before travel.
- Promethazine: The effects last for about 6-8 hours and the medicine should be taken 2 hours before travel. There are side effects like dry mouth and drowsiness.
- Cyclizine: This medication needs to be taken 30 minutes before travel.
- Dimenhydrinate chewing gum: This medication available in the form of chewing gum is absorbed through the cheek.
- Meclizine: This is not recommended for children below 12 years of age. This needs to be taken 1 hour before travel for the maximum effect.
Summary
- Motion sickness usually occurs when you’re in repeated motion in a vehicle or any other movement that can affect your inner ear. The sensory organs send conflicting signals to the brain, and this confuses the brain and leads to motion sickness. This is because the sensory organs perceive different signals.
- Symptoms include an upset stomach, nauseous, vomiting, dizziness, sweating, loss of balance, and headache.
- Variations in your genes can contribute to a risk of motion sickness. The G allele of SNP rs56051278 found in the GPD2 gene and the T allele of SNP rs61759167 found in the PRDM16 gene, are found to be associated with an increased risk of motion sickness.
- Children between the ages of 2 and 12 years and pregnant women are more likely to experience motion sickness.
- Certain remedies can help relieve symptoms of motion sickness during travel. Your doctor may prescribe certain medication that needs to be taken before travel to avoid symptoms.
References
https://www.healthline.com/health/motion-sickness
https://www.medicalnewstoday.com/articles/176198
https://www.webmd.com/cold-and-flu/ear-infection/motion-sickness#1
https://www.ncbi.nlm.nih.gov/pubmed/25628336
