Introduction
In principle, swelling of the joint can occur in any joint and can have various causes. The enlargement of the joint can be painless or painful and is often already visible from the outside.
Causes
A common cause of joint swelling is trauma in the sense of an injury, typically occurring in sports accidents. Muscle trauma is often the cause. Since every muscle or tendon attaches to a bone and thus often to a joint, a pulled or torn muscle can cause the joint to swell.
However, injuries to the joint structures themselves can also lead to joint swelling. These include contusions and capsule tears that the person affected suffers in a trauma. Frequent sports injuries, such as a torn meniscus or cruciate ligament, also lead to joint swelling in many cases.
Finally, damage to bony structures can also lead to joint swelling. Tiny tears cause an inflammatory reaction, as a result of which more fluid accumulates in the joint space. With the above-mentioned injuries, it is therefore both possible that an effusion leads to swelling of the joint and that a vessel in the joint ruptures, resulting in the accumulation of blood in the joint.
Symptoms
Which symptoms occur in the context of a joint swelling depends on the cause of the swelling. Basically, a joint swelling can be painful or painless and accompanied by various symptoms. Depending on the joint and the extent of the effusion, the swelling may already be visible from the outside.
If an inflammation is present, redness, overheating and fever may occur in addition to the swelling. If there is a traumatic cause, depending on the affected structure, this can lead to significant movement restrictions or abnormal mobility. A joint swelling can be accompanied by severe pain or be completely painless.
The pain may also be permanent or only occur when the joint is moved or under stress (e.g. in the knee joint when walking/standing). Whether pain is present or not can give an indication of the cause of the joint swelling. Thus, pain usually occurs in the context of an inflammation or trauma, but rheumatic diseases or arthrosis can also be accompanied by pain of varying intensity.
