How do I remove mold from my wall and ceiling in the bathroom.

https://www.hometalk.com/diy/clean/bathroom/the-best-way-to-remove-mold-mildew-with-2-ingredients-no-bleach-33077514

I would scrape the ceiling, get rid of the popcorn and treat the ceiling with mold cleaner/killer. Then tape and mud the ceiling, sand and paint with stain blocking primer such as Kilz and then stain blocking moisture resistant paint. When you have the ceiling uncovered, install a vent or it will happen again.

Since it is always damp in your bathroom, there is no way to keep it at bay unless you increase the circulation in the room so that it will dry out. You need at least a fan or dehumidifier and an open window (weather permitting). To help keep it at bay, clean with bleach water to help start the cleaning and killing process. Finish with vinegar rinse that will kill the remaining spores that weren't washed away. If the stains are there for good, Use Kilz or something like that to paint. When you clean the areas that are prone to mold and mildew, rinse with vinegar each time, even if there are no signs of it, this may keep it away longer by preventing spores from spreading in the moist environment. The most important thing you need to do is try to decrease the constant moisture.

The only way to prevent it from coming back is to provide ventilation. That is why building codes require it. Bleach is natural, with chlorine being a basic chemical element. Can't get more natural than that.

I think the only sure way to remove the mold is with a strong bleach solution. In order for it to stop coming back you will have to provide ventilation to the room, either by opening a window or installing a properly vented fan in the room.

Vented fan yes, what about a dehumidifier as a temporary help?

nds as if there is not enough ventillation! Get the Vent Cleaned out!