Introduction
A ganglion on the finger is colloquially called an over bone (in technical terminology, however, an over bone refers to a bony structure). A ganglion is a tumor that can develop on a joint capsule or tendon sheath. The ganglion is benign and prallelastic because it is filled with fluid. It is usually about the size of a pea, but it can also grow larger depending on its location. On the fingers, it occurs most frequently on the extensor side of the distal joint and on the flexor side of the metacarpophalangeal joint.
Causes of a ganglion
The exact origin of a ganglion on the finger is still unknown. However, it is certain that there is a connection with chronic irritation of the affected finger. The irritation leads to increased fluid formation.
The additional fluid no longer finds room in the joint; instead, the inner membrane of the joint capsule expands outwards through a weak point in the outer sheath. Such a chronic state of irritation can be caused by overstraining the fingers. However, frequent inflammatory processes, such as those occurring in the inflammatory disease rheumatism, can also cause a ganglion on the finger.
Not infrequently, however, ganglia on the fingers also occur spontaneously, without any recognizable mechanism of origin. In addition, trauma to the fingers is under discussion as the cause of a ganglion. What the ganglia have in common, regardless of their location, is that there is a connection between them and the joint space.
Through this so-called stalk, fluid can be exchanged between the joint and the ganglion. This is noticeable, for example, during movements of the fingers. The movement reduces the volume of the joint, the fluid is pressed into the ganglion space and the ganglion swells.
You can recognize a ganglion on the finger by these symptoms
The ganglion on the finger is typically located on the flexor side of the base joint or the extensor side of the finger end joint. There, it is conspicuous as a bulge, usually the size of a pea. The size may change when the affected joint is moved.
The ganglion is usually filled with a viscous fluid. Further symptoms are often pain in the affected finger and restricted movement of the joint. In addition, numbness and tingling may occur due to the constriction of nerves.
Circulatory disorders are also occasionally caused by ganglia, so that the affected finger turns whitish or, in cold weather, bluish. If the ganglion lies at the end of the finger, it can also cause nail changes. Besides the characteristic bump, pain is the main symptom of a ganglion on the finger.
The ganglion itself is usually very sensitive to pressure, and pain can also occur throughout the finger. Movement restrictions in the affected joint are also often caused by pain, but the ganglion can also simply act as a mechanical obstacle preventing movement. Depending on the position of the ganglion, the bending or stretching of the affected finger is more likely to be painful.
The ganglion (especially if it is larger) can also press on nerves, vessels, tendons and muscles. If nerves are constricted by the ganglion, so-called nerve pain can occur. Tingling and numbness can also be caused by irritation of the nerve.
If vessels are compressed, this can lead to circulatory disorders in the affected finger. Especially in cold weather, the finger turns white or blue very quickly. Such a reduced blood circulation can lead to tissue damage, which can also manifest itself as pain. The constriction of muscles and tendons not only results in a painful restriction of movement, it can also reduce the strength of the muscles.
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