KUWTK season premiere: Emotional Kim Kardashian is comforted by sister Kylie Jenner as she tests positive for lupus antibodies after suffering from joint pain

Kim Kardashian broke down in tears as her doctor revealed she's tested positive for lupus antibodies during Sunday's premiere of Keeping Up With The Kardashians.

Comforted by sister Kylie Jenner, the reality star, 38, admitted she'd been experiencing swollen joints, headaches and general fatigue ahead of the arrival of her fourth child Psalm, who was born via surrogate in May.

The TV personality - who also tested positive for rheumatoid arthritis (RA) - was reassured by Dr. Daniel Wallace as he said the results don't confirm the presence of the diseases.

Kim may have lupus and Kris breaks down in new KUWTK season.

As the show opened, the make-up mogul told her mother Kris Jenner that she'd been feeling tired and had to take a urine test to rule out pregnancy.

But as she played a game with her son Saint, three, later on, her hands went numb. Detailing her symptoms, she told sister Kourtney's ex Scott Disick, 36: 'I feel like I'm literally falling apart. I feel this, like, in my bones.

Kim - who shares North, six, Saint, Chicago, 19 months, and Psalm, three months, with husband Kanye West - Googled her symptoms and decided to visit Beverly Hills rheumatologist, Dr. Daniel.

With doting sister Khloé, 35, by her side, the brunette explained her hands were itchy and swollen.

The health specialist explained RA was the 'worst-case scenario', but he ordered the star to undergo some bloodwork.

Kim later caught up with Foodgod star Jonathan Cheban, 45, for lunch at new restaurant Burgerim.

While the socialite showed his BFF his phone charging case, Kim admitted she couldn't lift the device.

'I woke up and my hands were stiff,' she told him. 'I couldn't use my hands. I couldn't pick up my toothbrush. I couldn't do my bra. It was really bad.'

The businesswoman said in a confessional: 'I'm freaking out, I have a baby on the way and law school. You have to think about how much this is going to affect your life.'

Later into the episode, Kim - who was joined by Kylie, 22 - received a call from her doctor, who shared the shocking results.

Daniel explained: 'As far as your results. Your antibodies tested positive for lupus and Rheumatoid Arthritis.'

'You'd have, in addition to swollen joints, you'd have fevers, rashes, mouth sores, be really tired.'