Kardashian West, 38, also tested positive for rheumatoid arthritis antibodies after experiencing some concerning symptoms in her hands and joints that prompted a visit to her doctor for a blood test.
Her doctor also told her on the phone call that the results don't automatically mean she has either lupus or rheumatoid arthritis because there can be false positives in the screenings.
In other words, the screening tests used when someone has a suspected autoimmune disease, such as lupus or rheumatoid arthritis, include values that can be seen in normal, healthy people, said NBC News medical contributor Dr. Natalie Azar, rheumatologist with NYU Langone Medical Center. According to the American College of Rheumatology, the most common test performed to screen for lupus is positive in up to 15% of the healthy population.
Kardashian West scheduled a follow-up appointment, but shared her fears after getting the news.
"You know, you really do get in your head and think about the worst possible things that can happen,'' she said. "So for the next few days, it’s going to be really hell ... wondering what I have, what’s going on and how to fix this."
The reality TV star detailed her symptoms earlier in the episode.
"I’ve been feeling so tired, so nauseous and my hands are really getting swollen," she said.
She ruled out pregnancy and her carpal tunnel syndrome as the potential source of her health issues.
"Lately, my wrists have started to hurt again but it’s definitely a different feeling than before," she said. "I feel this in my bones. It’s starting to really worry me. I really have to look into this."
"I have a baby on the way, I have law school," she said. "It just can really scare you when you start really thinking about how much this is going to really change my life."
Lupus is a chronic autoimmune disease that can attack any part of the body, including the joints, skin, kidneys and lungs, according to the Lupus Foundation of America.
It most commonly occurs in women of childbearing age and is more likely to occur in women of color. Symptoms can also include cognitive issues, disfiguring rashes and painful joints.
Singer and actress Selena Gomez revealed in 2017 that she underwent a kidney transplant as a result of having lupus.
Rheumatoid arthritis is an autoimmune disease in which the body’s immune system mistakenly attacks the joints, causing inflammation, joint pain and swelling, according to the American College of Rheumatology.
It affects more than 1.3 million Americans, about three-quarters of whom are women. The disease most often begins between ages 30 and 50.
Kardashian West has said she also has psoriasis, which can put her at risk of another autoimmune disorder.
After receiving the call from the doctor, Kardashian West was consoled by her mother, Kris Jenner.
"Let's stay really positive until we get some results,'' Jenner said.