I have slept for 55 years, that's 20,075 nights of sleeping. that I woke up just fine. Slept on my right, on my left... on my back and on my stomach... But ONE time I wake up with Vertigo thats originates from my left ear, and I vow to never sleep on my left side again! But I sleep so good on my left side!
And no, I don't have vertigo.. but PTSD keeps me sleeping on my right!