What do you suggest if my left thumb hurts when lifting heavy weights?

Thumb pain. can be joint, ligament or nerve or tendon related among other things. A injured joint that is swollen, a ligament injury for example in a collateral ligament, or a nerve that has been bruised or forming a neuroma. A tendon that is inflamed may be putting too much stress on structures.such as a tendon leading to tendonitis If this continues. Gloves may help if not an eval w hand surgeon.