What does it mean when your hands are cold? does it indicate a low metabolism, bad circulation or something else? please say all possible causes.

From nothing: To possible arterial blockages. Check, blood pressure, pulses, have an exam . Some other conditions, diabetes, endocrine issues can cause the feeling without any critical blockages.

Possibly Raynaud's: For some this may represent raynaud's syndrome, a spasm of the small vessels of the hands most often related to cold weather, emotional stress, or a multitude of other factors. Classically it is described as cold hands which first turn "ghost white" and then become purplish in color, most often trigged by the cold. I would suggest seeing a vascular surgeon to test for circulatory problems.