wasting vs wasting away

wasting and wasting away both are nouns.

Word	Noun	Adjective	Verb	Adverb
wasting	Yes	No	No	No
wasting away	Yes	No	No	No

As nouns, wasting and wasting away are synonyms defined as:

wasting and wasting away: a decrease in size of an organ caused by disease or disuse

Other synonyms of wasting include atrophy.

wasting (noun)	wasting away (noun)
a decrease in size of an organ caused by disease or disuse	a decrease in size of an organ caused by disease or disuse
any general reduction in vitality and strength of body and mind resulting from a debilitating chronic disease