Related by context. Frequent words. (Click for all words.) 33 persistent 26 chronic 24 pervasive 24 nagging 20 debilitating 20 continuous 18 enduring 17 lingering 17 persists 17 troublesome 17 longstanding 16 robust 16 dogged 16 recurring 16 sporadic 15 acute 15 prolonged 15 hampered 15 stymied 15 severe 15 persistence 15 relentless 14 continual 14 plagued 14 stubborn 14 sustained 13 periodic 13 heavy 13 widespread 13 perpetual 13 concerted 13 plague 13 pressing 13 erratic 13 constant 13 persist 12 exacerbated 12 afflicted 12 consistent 12 steady 12 compounded 12 beset 12 persisted 12 occasional 12 mild 12 protracted 12 Serious 12 rash 11 continuing 11 intense 11 mounting 11 perennial 11 hindered 11 endured 11 prevalent 10 rampant 10 frequent 10 perceived 10 susceptible 10 overcame 9 rife 9 weak 9 linger 9 resilient 9 despite 9 Continued 9 overcoming 9 renewed 9 forceful 9 intensifying 9 repeated 8 heightened 8 overcome 8 ongoing 8 vigorous 8 crippling 8 slight 8 worsening 8 troubling 7 combating 7 spite 7 nasty 7 entrenched 7 intensified 7 continued 7 induced 7 aggressive 7 growing 6 serious 6 ferocious 6 eradicate 5 battling 5 recent 4 riddled 4 strong 4 fierce 4 worrisome 3 increasing 3 prone 2 escalating 1 rising