Synonyms for Swelling:

n.

blackhead, blotch, black eye, blemish, athlete's foot, bedsore. perforation, complication, etiology, discharge, aetiology, crisis, pathology, hallucination, chill, dehydration. augmentation (noun)
annex, addendum, enlargement, amalgamation, addition, adjunct, appendix, increase, extension, augmentation, inflation.
bulb (noun)
corn.
bulge (noun)
intumescence.
expansion (noun)
development, distension, growth, fattening, lengthening, amplification, broadening, crescendo, expansion, burgeoning, magnification, stretching, engorgement, dilation, spreading, increment, thickening, widening.
physical growth; lump (noun)
contusion, weal, blister, abscess, increase, wale, boil, pock, wart, inflammation, corn, sore, injury, ridge, tumor, dilation, puffiness, bunion, pustule, carbuncle, pimple, enlargement.
swelling (noun)
intumescency, lump, puffiness, intumescence, injured.
tumor (noun)
growth.
welt (noun)
wen, abrasion, blister, pock, contusion, boil, carbuncle, wart, abscess, bunion, sore, pustule, suppuration, pimple, wale, corn, injury, ridge, weal, tumor, inflammation.

v.

expanding (verb)
growing, expanding, Inflating, Enlarging, Engorging, increasing, Magnifying, Extending, augmenting, Amplifying, incrementing, Dilating, Distending, developing.

Other synonyms:

pimple, injury. neoplasm
tumor.
soreness
inflammation.
Other relevant words:
pock, suppuration, bunion, wale, pimple, tumor, pustule, wart, carbuncle, lump, intumescency, blister, abrasion, wen, inflammation, abscess, sore, intumescence, injured, boil, contusion, injury, puffiness, corn.

Usage examples for swelling

  1. Honestly, I felt my neck swelling up inside my helmet. – Project Hush by Philip Klass
  2. He felt a swelling of the throat. – The Desert Fiddler by William H. Hamby
  3. It generally begins about the third day after birth with swelling of the lid of one or other eye, though both are soon involved. – The Mother's Manual of Children's Diseases by Charles West, M.D.