Related Clues:

• Agitate
• See 31-Across
• Sign of stress
• To-do
• Not have peace of mind
• Gripe
• 'No ___!' ('Easy!')
• Elbow grease
• Act the mother hen
• Tempest in a teapot
• Raised area on a neck
• Sweat bullets
• Be a worrywart
• Fingerboard feature
• Guitarist's worry?