in pain
Synonym discussion
Sense: idiom/1
'In pain' describes a state of physical or emotional distress and is the most neutral and commonly used expression. 'Suffering' is broader—it can cover long-term physical illness, emotional grief, or hardship—and carries a slightly more serious or formal tone ('the patient is suffering greatly'). 'Hurt' feels more direct and is often used in everyday speech for physical injury ('my back hurts'), but can also describe emotional wounds ('I was hurt by her words'). 'Aching' narrows the meaning to a dull, continuous physical discomfort and is less common for emotional distress. Choose 'in pain' for a clear, general statement; 'suffering' for a deeper or longer struggle; 'hurt' for a more personal, conversational tone; and 'aching' when the pain is steady and throbbing.
Etymology
The phrase 'in pain' comes from the Old French word 'peine' (meaning suffering or punishment), which in turn comes from Latin 'poena' (penalty, punishment). The preposition 'in' signals being within a state, so 'in pain' literally means 'within a state of suffering'. Over time, the meaning shifted from punishment-related suffering to general physical and emotional distress.