Infectious arthritis (septic arthritis) is caused by a bacterial, viral, or fungal infection inside a joint. The infection may be caused by an illness or may spread from an infection in a wound near a joint.

The large joints, such as the hips, knees, shoulders, and elbows, are most often affected. Infectious arthritis usually affects one joint, but it can affect many joints. Symptoms may include:

• Severe pain with the slightest joint motion or pressure on the joint.
• Fever and chills.
• General weakness and headache.
• Painful, red, swollen, and stiff joint.
• Red streaks near the joint.
• Swollen lymph nodes.

Immediate treatment with antibiotics and, possibly, surgical drainage of the affected joint can prevent the spread of the infection, the destruction of the joint, and even death.