suffering vs irritation

suffering and irritation both are nouns.

Word	Noun	Adjective	Verb	Adverb
suffering	Yes	Yes	No	No
irritation	Yes	No	No	No

As nouns, irritation is a hyponym of suffering; that is, irritation is a word with a more specific, narrower meaning than suffering:

Other hyponyms of suffering include agony, torment, torture, throes, discomfort, soreness.

suffering (noun)	irritation (noun)
feelings of mental or physical pain	unfriendly behavior that causes anger or resentment
psychological suffering	the act of troubling or annoying someone
a state of acute pain	an uncomfortable feeling of mental painfulness or distress
misery resulting from affliction	a sudden outburst of anger
	the psychological state of being irritated or annoyed
	the neural or electrical arousal of an organ or muscle or gland
	(pathology) abnormal sensitivity to stimulation

suffering (adjective)	irritation (adjective)
troubled by pain or loss
very unhappy; full of misery