double up vs double over

double up and double over both are verbs.

Word	Noun	Adjective	Verb	Adverb
double up	No	No	Yes	No
double over	No	No	Yes	No

As verbs, double up and double over are synonyms defined as:

double up and double over: bend over or curl up, usually with laughter or pain

Other synonyms of double up include double.

double up (verb)	double over (verb)
stake winnings from one bet on a subsequent wager	bend over or curl up, usually with laughter or pain
bend over or curl up, usually with laughter or pain
share a room or a bed designed for only one person