Bunions are large bumps on the inside of the foot, at the joint just below the big toe (the 1st metatarso-phalangeal joint). Bunions are usually a combination of abnormal bone growth and a swollen bursal sac (soft tissue fluid sac).
Bunions often cause the big toe to deviate towards the outside of the foot, sometimes causing the 2nd toe to lift up and sit on top of the big toe.