Pain is transmitted to the brain from sensory nerves and may be a symptom of an underlying pathological condition, such as inflammation. It may also be due to other causes, such as bruising, infection, burns, headaches, and sprains and strains. Arthritis can be due to aging, biochemical changes, or an autoimmune problem that primarily affects joints, causing pain, swelling, and stiffness. The following conditions are related to pain and arthritis.