The diagnosis and management of a colder hand includes evaluation by internists, rheumatologists, cardiologists
, and others.
There are a number of different causes that may explain by one hand is perpetually colder than the other. This potentially could be positional or related to clothing suggesting asymmetrically exposing one side of your body more than the other. The sensation of one hand being colder than the other could be a nerve problem leading to abnormal sensation, such as a neuropathy or radiculopathy.
As you have suggested, this could be related to poor circulation. This means, there could be a blockage in one of the arteries going to your hand. Or it could be that at times, certain factors can suddenly cause the arteries in that hand to become smaller (also known as Raynaud's phenomenon), which is common.
It is not possible to make a diagnosis without seeing the patient in person. It is, therefore, the strong recommendation to be evaluated by an internist