Kim Kardashian Feels ''So Bad'' for Kendall Jenner After Learning About Her Health Battle

On Sunday's episode of Keeping Up With the Kardashians, Kendall reveals to Kim Kardashian that she's been struggling with sleep paralysis
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When Kendall tells Kim that she's "so tired" in the clip above, Kim asks Kendall "what's been going on?"

Kendall tells Kim, "This stupid sleep paralysis thing is really getting to me."

"Sleep paralysis?" Kim asks.

Kendall then explains that sleep paralysis is when, "You're asleep and then in the middle of the night, basically your mind wakes up but your body is still asleep. So like you wake up but nothing can move, can't speak, nothing."