Same word as qualm:

agitation, anxiety, apprehension, compunction, conscience, demur, disquiet, foreboding, hesitation, indecision, insecurity, misdoubt, misgiving, mistrust, nervousness, objection, pang, perturbation, presentiment, regret, reluctance, remonstrance, remorse, scruple, suspicion, twinge, uncertainty, unease, uneasiness