Your dog lavishing a sloppy, wet tongue all over you is indeed a sweet thing, but if the behavior gets excessive, it can be frustrating too. Canine hand licking can point to everything from a friendly "hello" to feelings of anxiety -- and maybe even a little bit of both.
Obedience
If a dog nervously licks your hands, it may just be his way of communicating that he is obedient and subordinate to you. This doggie doesn't feel dominant over you, and acknowledges that you're the leader in his world. Hand licking is often a modest act in the realm of canine body language.
Welcome
A dog may lick your hands as a way of giving you a warm welcome. By licking you, your pooch is letting you know how appreciated you are. In some cases, however, this "welcome" licking can also arise out of a blend of welcome feelings and the aforementioned feelings of subordination. By licking your hand, a dog may be "buttering you up," canine style, to stay on good footing with you.
Grooming
By licking your hand, your doggie may just be giving you a nice grooming -- trying to get you all neat and clean. When animals groom each other, the behavior is referred to as "allogrooming."
Licking Up the Salt
If your dog licks your hands a lot, it may be he's simply lapping up the natural salt content in your skin. Your pooch may not necessarily be trying to be loving -- he may just think that your hand has the flavor of a yummy french fry. He may even be fond of the sweet smelling hand cream on your skin, strangely enough.
Compulsion
When a dog's hand licking habit seems excessive and perhaps even out of control, it may signify a compulsive behavior pattern, not unlike immoderate barking or tail chasing. Whether a dog is obsessed with licking the walls of your bedroom or your hand, a compulsion may just be responsible. A lot of different factors can trigger compulsions in dogs, including extended separation from a beloved caretaker, isolation, insufficient experience with playmates and past physical harm and neglect. If your dog's hand licking habit seems to be an urge that he cannot help, an appointment with the veterinarian is definitely a smart idea.