I'm really worried about my mom. She's 49 and dealing with a thyroid problem, but now she's tested positive for Covid. Her HR CT report seems fine, and she's mainly experiencing weakness and a bit of a dry cough. Her oxygen levels are usually between 93 to 98 during the day, but at night while she's sleeping, her spo2 level drops quickly to around 80-85, which is pretty alarming. We end up waking her up, and then her spo2 levels return to normal. Could this be because of Covid? Should I be worried? What should we do if this happens again?