What is Lupus? Kim Kardashian in 'scary head space' after health scare

Kim Kardashian broke down into tears on the season premiere of Keeping Up With the Kardashians after testing positive for lupus, an autoimmune disease that occurs when a human body's immune system attacks its own tissues and organs.

"Lately, my wrists have started to hurt again, but it's definitely a different feeling than before. I feel this, like, in my bones," the reality TV star said on the premiere episode on Sunday. "I just am, like, freaking out... It just really can scare you when you start really thinking about how much this is gonna really change my life."

Kim was accompanied by her sister Khloe to the doctor's office where the health scare was revealed.

"The worst-case scenario is that this is the start of a systemic process, rheumatoid arthritis. But until I see some of your blood work, I won't really know," the doctor Kim.

The mother-of-four was already suffering from some painful physical symptoms including swollen joints, headaches, general fatigue, following which she decided to undergo a blood test.

"You really do get in your head and think about the worst possible things that can happen," Kim said on the episode. "So, for the next few days, it's gonna be really like hell living, wondering what I have, what's going on, and how to fix this."

During Sunday's premiere, Kardashian live-tweeted, saying:

The most common signs and symptoms of lupus are Fatigue; Fever, Joint pain, stiffness and swelling; Butterfly-shaped rash on the face; Skin lesions; Shortness of breath; Chest pain; Dry eyes; Headaches, confusion and memory loss.

Inflammation caused by lupus can affect many areas of your body including kidneys, lungs, heart, brain and central nervous system, and blood vessels.

According to the Lupus Foundation of America, nearly 1.5 million people in the US have lupus.