My husband broke his hand has a half cast on but swelling is gettin worse do i take him back in or is it healing?

Have it reevaluated: The cast may be too tight or there may be an issue with the hand area itself/ He needs to return to the doctor who casted the hand.

Time course?: It is common for fractures to swell in the first couple of days after an injury. This is likely to be worse if he has not been elevating it/wearing a sling. If the pain is not severe and the colour in his fingers looks normal then try elevating it and see if it improves. But if the pain is severe then getting it reviewed is sensible - sometimes we need to loosen the plaster a bit.

Difficult : To answer precisely without assessment as swelling occurs after fractures but also could indicate an ongoing issue not being sorted by the current cast/cast problem. See doctor and urgently if pale cold periphery or severe pain