alleviate : make (suffering, deficiency, or a problem) less severe.
aggravate : make (a problem, injury, or offence) worse or more serious.
moderate : average in amount, intensity, quality, or degree.
abate : (of something unpleasant or severe) become less intense or widespread.
relieve : cause (pain, distress, or difficulty) to become less severe or serious.
Synonym of
relieve is
alleviate