compulsion vs obsession

compulsion and obsession both are nouns.

Word	Noun	Adjective	Verb	Adverb
compulsion	Yes	No	No	No
obsession	Yes	No	No	No

As nouns, compulsion and obsession are synonyms defined as:

compulsion and obsession: an irrational motive for performing trivial or repetitive actions, even against your will

compulsion (noun)	obsession (noun)
using force to cause something to occur	an unhealthy and compulsive preoccupation with something or someone
an irrational motive for performing trivial or repetitive actions, even against your will	an irrational motive for performing trivial or repetitive actions, even against your will
an urge to do or say something that might be better left undone or unsaid