The condition and the treatment
Rheumatoid arthritis is a condition that causes pain, swelling and inflammation in your joints. Symptoms usually come and go, but can sometimes get much worse, and this is known as a 'flare-up'. Over time, the joints become damaged and stop working properly. The damage is caused when the body's immune system, which normally fights infection, goes wrong and starts to attack healthy joints. People with severe active rheumatoid arthritis have a high level of joint inflammation and pain, which affects their ability to carry out everyday tasks.
Tocilizumab is a drug that helps to reduce the pain and swelling caused by rheumatoid arthritis. It may slow down the progression of the condition and help to prevent permanent joint damage.
NHS Choices may be a good place to find out more.