Symptomatology
Motion sickness is polysymptomatic. Nausea and vomiting may be accompanied by a host of significant symptoms including headache, sopite (drowsiness), sweating, facial pallor, cold sweating, increased salivation, sensations of bodily warmth, dizziness, and, unsurprisingly, loss of appetite and increased sensitivity to odors. The importance and negative impact on performance of sopite is underestimated, and yawning has been shown to be a behavioural marker. The headache provoked can be migrainous and disabling. Gastric dysrhythmias may provide a marker of nausea in motion sickness, and drop in stomach fundus and sphincter pressure correlates with nausea.