"Nauseated" = feeling sick, experiencing nausea; "nauseous" = causing nausea, sickening.
Adjective: FEELING sick, experiencing the discomfort of nausea. "I feel nauseated" = I feel sick to my stomach. This is the prescriptively correct form to describe a PERSON experiencing nausea. Comes from "nauseate" (to cause nausea or to feel it).
She felt nauseated during the first trimester of her pregnancy and struggled to eat in the mornings.
The rough sea crossing left most of the passengers nauseated and reaching for the sick bags.
The medication may leave you feeling nauseated for the first few days — take it with food to reduce discomfort.
Prescriptive adjective: CAUSING nausea. "A nauseous smell" = a nauseating smell that provokes sickness. A chemical, smell, or situation is "nauseous" if it causes others to feel ill. Modern usage: today "nauseous" is widely used (even by doctors) to mean "feeling sick", though purists flag this as incorrect.
The nauseous fumes from the paint nearly overcame the workers who were renovating the basement without ventilation.
The doctor asked if the patient was nauseous, using the modern colloquial sense of the word.
There was a nauseous quality to the rotting fruit that made entering the storage room unpleasant.
Common mistake
"I am nauseous" should mean "I am nauseating / I cause others to feel sick" (like saying "I am poisonous"). The prescriptively correct form is "I am nauseated" = I feel sick. However, the use of "nauseous" to mean "feeling sick" is so widespread today that nearly all modern dictionaries accept it. It is a prescriptive battle lost in everyday speech, but in formal writing and medical contexts, using "nauseated" for "feeling sick" is more precise and unambiguous.
Trick to remember it
Think of the parallel with other "-ous" words that mean CAUSING or BEING something: "poisonous" = causing poison. "Nauseous" = causing nausea. So "I feel nauseous" is technically like saying "I feel poisonous" = I make others sick (odd if you just mean YOU feel sick). Correct: "I feel nauseated" = I experience nausea. In practice: say "nauseated" when you want to be precise. Nobody will correct "nauseous" in casual speech, but "nauseated" is unambiguous in formal writing.
Quick rule
Nauseated = feeling sick (describes the person experiencing the discomfort). Nauseous = causing nausea (describes what produces the discomfort) — though in modern usage both are used interchangeably.
Did you know?
The prescriptive distinction between "nauseous" and "nauseated" is a classic example of a grammatical rule that has been overtaken by usage. The Oxford English Dictionary documents "nauseous" in the sense of "feeling sick" since the 17th century — long before 20th-century prescriptivists tried to "correct" it. In medicine, most healthcare professionals today use "nauseous" and "nauseated" interchangeably, and modern medical style guides accept both forms.
Exercise 1 · Pick the right one
After eating the suspect shellfish, three of the diners felt _____ and asked to lie down before the symptoms worsened.
Exercise 2 · Pick the right one
The _____ smell coming from the fish market on a hot day made passersby cover their noses as they walked past.
Exercise 3 · Form the word
Nauseated = feeling sick (describes the person experiencing the discomfort). Nauseous = causing nausea (describes what produces the discomfort) — though in modern usage both are used interchangeably.
"I am nauseous" should mean "I am nauseating / I cause others to feel sick" (like saying "I am poisonous"). The prescriptively correct form is "I am nauseated" = I feel sick. However, the use of "nauseous" to mean "feeling sick" is so widespread today that nearly all modern dictionaries accept it. It is a prescriptive battle lost in everyday speech, but in formal writing and medical contexts, using "nauseated" for "feeling sick" is more precise and unambiguous.
Think of the parallel with other "-ous" words that mean CAUSING or BEING something: "poisonous" = causing poison. "Nauseous" = causing nausea. So "I feel nauseous" is technically like saying "I feel poisonous" = I make others sick (odd if you just mean YOU feel sick). Correct: "I feel nauseated" = I experience nausea. In practice: say "nauseated" when you want to be precise. Nobody will correct "nauseous" in casual speech, but "nauseated" is unambiguous in formal writing.
Bryan López
Founder of SpeakUP Academy