worrisome (adj.)

• aggravating
• annoying
• bothersome
• disquieting
• distressful
• distressing
• disturbing
• exasperating
• galling
• importunate
• irksome
• irritating
• pesky
• pestering
• pestiferous
• pestilent
• pestilential
• plaguey
• provoking
• teasing
• tiresome
• troublesome
• troubling
• upsetting
• vexatious
• vexing
• wearisome
• worrying