I have a golf ball sized, hard, painful lump on the inside of left arm where the arm bends. it grew kind of suddenly. i've had it for about 2 weeks. ?

Lump on elbow: Could be an abscess, a bursitis ( that grows suddenly and an abscess keeps growing ) that is infected or is not infected or gout. if bursitis sometimes comes on suddenly from repetitive work , need to rest,ice ,NSAIDS and may get it drained and fluid checked . Also lyme can present this way and needs treatment f/u with doc/urgent care