What does it mean to dream about nausea?
Nausea in a dream often marks a sense of something you cannot stomach, and what turned you sick is usually the thread worth following back into waking life.
Four ways to read it
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream.
Freud
Freud would read nausea as the body's way of refusing something the mind cannot take in, a disgust that has found a physical form. He held that revulsion in sleep can mark a wish or memory the self wants to expel. The sickness may point to something the waking self cannot swallow.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
Jung would see nausea as the psyche rejecting what does not agree with it, an instinct that something must be put out. He treated such revulsion as a signal worth heeding, a refusal that protects the self. The sickness can mark something the self is right to turn away from.
Jungian concept (our summary).Modern
Continuity research ties dream nausea to waking disgust or distress the mind carries into sleep, and bodily feeling can shape the image too. The sense of being unable to stomach something often echoes a real revulsion. The sickness is best read against what you cannot abide awake.
Continuity hypothesis (our summary).Mythological
Myth used the turning stomach as a sign of the unclean, the food that should not be eaten, the sight that no one could bear. Disgust marked the boundary of what was permitted. Across cultures such revulsion warned of the tainted and the forbidden.
Rosmerta Publishing editorial synthesis (after Bulfinch; Frazer).