Can you work with a fresh hematoma? its a high pace work environment that requires a lot of arm work. the hematoma is on my left arm?

You should put a cold pack to prevent the hematoma from getting larger. Apply a bandage that mildly compresses the area. It would be preferable to rest the affected arm. If you can work without taking your left arm, you may continue working.

hematoma meaning a bruise - yes - the arm will likely be sore and sorer if your left arm is your dominant one. Ice or heat - whichever feels better will help. What was the cause of the hematoma? If the pain gets worse I would stop.