Hi, Thank you for your question my name is Dr. Jared Marcucci MD and I will try to help answer your question. A bump on wrist could be a number of different things but from your description it sounds like you may have a ganglion cyst. Ganglion cysts are the most common mass or lump in the hand or wrist. They are not malignant. in fact usually they are harmless. They occur in various locations, but most commonly develop on the back of the wrist. Ganglion cysts can appear and disappear and change in size. often ganglion cysts do not require treatment. However if the cyst is painful, interferes with the ability to use the wrist or hand or has an unacceptable appearance, there are several treatment options available. It is important that you have it evaluated to determine what the growth in your wrist is and how to treat it. There are other things besides a ganglion cyst, it could be an abscess, an enlarged lymph node or other type of growth. I hope that this helps answer your question. Sincerely, Dr. Jared Marcucci