Autoimmune reactions can cause inflammation in joints, and sometimes neighbouring tissues. Rheumatoid arthritis falls within this class, with swollen and painful joints, and sometimes tiredness, depression, mood changes and flu-like symptoms.7

Gout is the most common form of inflammatory arthritis, affecting 2.5 per cent of adults. A build up of uric acid and urates as needle-like crystals in joints makes it extremely painful, as it can have a sudden onset.

Other inflammatory arthritis conditions include ankylosing spondylitis (affecting the spine), psoriatic arthritis (associated with or before psoriasis develops and often experienced as swollen toes or fingers), and reactive arthritis. Sometimes known as Reiter's syndrome, this is usually associated with infections, typically in the bowel, with chlamydia or other sexually transmitted infections, or occasionally throat infections. In addition to painful joints, there can be conjunctivitis or non-gonococcal urethritis, but symptoms tend to disappear within six months.7,8