What is lupus, and how is Selena Gomez being treated?
Lupus is incurable and difficult to diagnose, with the American star describing the autoimmune disease as "very misunderstood".
Thursday 14 September 2017 17:06, UK
Two years after being diagnosed with lupus, Selena Gomez has had a kidney transplant. But what do we know about the "complex and poorly understood" disease?
The star is among several celebrities who have suffered with the illness - including Toni Braxton, Kelle Bryan and the late Michael Jackson.
Here are some of the most commonly asked questions about the condition.
What is lupus?
Lupus is an incurable immune system illness. It is believed to be genetic in origin - and women are affected in 90% of cases. You are more likely to suffer from lupus if you are of African or Asian descent.
With lupus, the immune system (the body's defence system) turns against the body and produces too many antibodies - causing harm to organs and tissues, principally the kidneys and skin.
Organs are often damaged irreversibly, meaning many lupus sufferers have transplants.
How can I catch lupus?
Lupus is not infectious, nor is it contagious. Often, lupus patients have family members with autoimmune conditions or illnesses such as multiple sclerosis or diabetes.
According to Lupus UK, other triggers appear to include viral infections, strong medication, sunlight, childbirth and the menopause.
What are the symptoms of lupus?
Two main symptoms of lupus are joint and muscle pain, as well as an extreme tiredness that persists despite lots of rest.
Other symptoms include depression, rashes, headaches, anaemia, fevers, hair loss and mouth ulcers.
Doctors often misdiagnose lupus due to the variety of symptoms, but normal tests include urine and blood tests.
How can you treat lupus?
Usually, diagnosing lupus is not straightforward. But once diagnosed, it is generally treated using anti-malarials such as hydroxychloroquine, and non-steroidal anti-inflammatory drugs.
Steroids such as prednisolone have been critical for improving the lives of lupus patients. Immunosuppressants are used in more severe cases.
If your kidneys fail, you can be treated with dialysis or a kidney transplant.
Despite being incurable, most patients can anticipate a normal lifespan.