inconvenience

discomfort, fleabite, pinprick

affront, insult, offense (or offence)

upset, worry

affliction, albatross, burden, cross, curse, menace, millstone, plague, sore

anxiety, plight, predicament, tribulation, trouble

hang-up, pet peeve, problem

annoyer, disturber, harasser, mischief, offender

pandora's box

burden, encumber, saddle, weigh

fetter, hamper, hamstring, handicap, hinder, hobble, hold back, hold up, impede, inhibit, interfere (with), manacle, obstruct, shackle, tie up, trammel

aggravate, anger, annoy, bother, bug, chafe, exasperate, gall, get, irk, nettle, peeve, pique, rile, vex

grate, inflame (also enflame), provoke

agitate, perturb, upset