"This is pretty serious as you can see," Bieber said.
"I wish this wasn't the case but obviously my body is telling me I have to slow down. I hope you guys understand and I'll be using this time to just rest and relax and get back to 100 per cent so I can do what I was born to do."
Bieber then went on to say he is doing everything he can to get better and thanked fans for their encouragement and support.
"I'm going to get better," Justin promised. "I'm doing all these facial exercises to get my face back to normal and it will go back to normal. It's just time. We don't know how much time it will be but it's going to be okay. I have hope and I trust God. I trust that this is all for a reason and I'm not sure what that is right now, but in the meantime, I'm going to rest."
Bieber captioned the video "Important please watch. I love you guys and keep me in your prayers".
The comment section was quickly flooded with support for the pop star from fans and many of the star's famous friends and family.
Chelsea Bieber, the star's step mum said "Love you! Rest rest", while Romeo Beckham commented "love you bro" and his manager Scooter Braun said "Love you and proud of you".
Fans commented with love hearts and told the singer they were praying for him.
The model, 25, was rushed to hospital in March after suffering symptoms from a blood clot to her brain.
She has since made a full recovery, but a source has revealed to People that her husband is struggling to sleep and "stays up watching her as she rests".
A source said, "Justin is probably more traumatised than Hailey. Now that she's okay he's going to keep an eye on her and help her however he can. It shook him up."