Why is the palm of my left hand swollen ? should i b worried ?

Exclude infection: It is rare to have swelling in this area, and the first thing to be excluded would be an infection; as you are in Belize, I would consider also unusual, slow growing infections such as those in the tuberculosis family, called 'atypical mycobacteria' some of which are present in marine environments. Hand infections can be serious, so please seek qualified medical attention.