What causes lupus?
Your immune system makes proteins called antibodies that fight infection. In lupus, the body also makes autoantibodies that attack the body's own tissues. We're not sure why this happens – but it's probably due to a combination of environmental, hormonal and genetic factors.
Lupus isn't directly passed on from a parent to their children, but if you have a close relative with lupus you're at increased risk of developing it. Similarly, if you have lupus there's about a 1 in 100 chance of your child developing it in later life.
Lupus isn't contagious, so you can't catch it from anyone else.