Table 1.

The progression of seasickness described in accounts published between the mid-19th and early 20th centuries (Beard, 1881; Byrne, 1912; Chapman, 1864; Liveing, 1873; Skinner, 1894). The symptoms and signs have been grouped and color-coded to correspond to the framework in Figure 1.

Earliest	Early mild	Milder phases	More severe	Severe
Consciousness of respiratory movements	→	Abdomen and thorax movements
Long, deep breaths
	”Lump-sensation” in the throat and/or stomach	burning sensation in the stomach	”swallowing to keep it down.”	Retch Emesis
			nausea increased salivation
	Eructations	→
Intermittent familiar “queer feeling all over”	”queer sick feeling” in the head	→
			that dreadful “dolor cerebri” familiar to all who have suffered from sea sickness
Disinclination for work	→	→
Irritability of temper with tendency to worry about trifles	→	→
		Fullness and lightness in the head
Headache (Slight)	→	Occipital headache especially a sense of tension in the occipital region	Headache
Scalp paraesthesias	→	Olfactory sensitivity/aversion Fullness or ringing in the ears Flushing of the face