Ache
Anguish, pain, ache, torment, discomfort, heartbreak, wretchedness, grief, sadness, desolation, trouble, anxiety, uneasiness, angst, suffering, agony, affliction, torture, heartache, misery, sorrow, woe, unhappiness, despair, worry, perturbation, and disquiet.
Difficulty
Danger, difficulty, jeopardy, hazard, imperilment, instability, peril, trouble, risk, endangerment, insecurity, and precariousness.
Tribulation
Hardship, tribulation, ill/bad luck, calamity, deprivation, destitution, impoverishment, need, lack, dire straits, adversity, misfortune, trouble, poverty, privation, indigence, penury, want, and beggary.
Pain
Cause anguish to, pain, make miserable, grieve, trouble, bother, perturb, disquiet, vex, torment, afflict, curse, plague, cut up, worrying, painful, agonizing, tormenting, saddening, heartbreaking, tragic, disturbing, unsettling, shocking, gut-wrenching, cause suffering to, upset, make wretched, sadden, worry, arouse anxiety in, disturb, agitate, harrow, torture, rack, oppress, dog, upsetting, affecting, traumatic, harrowing, sad, pitiful, heart-rending, haunting, concerning, disquieting, alarming, and distressful.