Lately, I have been sleeping and I wake up finding it very hard to breathe. I am on oxygen all of the time. I keep a pulse oximeter by my bed & check my pulse ox whenever something weird is happening with my breathing. Whenever this happens, I feel weird & heavy (I can barely lift a limb) and when I check my pulse ox and it shows low 70's - between 71-73. I'm not sure how long they last, but I have to sit straight up in the bed. It feels like the air goes down my throat & then stops. Once I can get out of bed, I sit at my desk and do a breathing treatment on the nebulizer. I have an appointment with my pulmonologist next week. I'm a stage 3 breast cancer survivor and have been in remission for 5 years. I've got so many side effects, I don't even know where they are coming from.