Ganglion cysts are the most common cause of a lump around the wrist. They are collections of fluid and usually nothing to worry about, but can sometimes be uncomfortable or unsightly.
Ganglions are caused by degeneration of a small part of the lining of a joint or tendon sheath. They can occur after wrist injuries and are sometimes related to arthritis but more commonly have no obvious underlying problem.
Sometimes there is just an awareness of a lump on the front or back of the wrist joint. Sometimes they can become painful, particularly at the limits of movement if they become compressed. Rarely they can cause tingling and numbness if they cause pressure on a nerve.
Ultrasound is usually the best method of confirming the diagnosis and point of origin of the ganglion. For larger or unusual ganglions an MRI scan can provide more useful information.
A combination of ultrasound and clinical examination is usually enough for a confident diagnosis of a wrist ganglion.