First, the mold grew on the wall because the wall is wet. You must find the source of the moisture. Second, correct the problem that is causing the moisture. Third, you need to follow careful instructions on cleaning up the mold. Dead or Alive mold can be harmful to you.

It is impossible to get rid of all mold and mold spores indoors, but indoor mold growth can be controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and also fix the water problem. If you clean up the mold, but don't fix the water problem, the mold problem most likely will return. See similar questions...

A small dot on the room side of a wall can mean that the inside of the wall is covered with black mold. A through inspection is recommended. See similar questions...

Black mold has the potential to cause health problems. Black Mold spores produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mildews are common. They can be immediate or delayed. See similar questions...

That depends on you or others in the home. Each of us react differently to moulds. All moulds are allergins. Some moulds have mycotoxins that are harmful. You should consult with a doctor trained in this area. See similar questions...

You have probably heard a great deal about black mold or toxic mold. It is usually associated with Stachybotrys chartarum , a greenish-black mold that is often found after there has been persistent water damage. See similar questions...

No. Although bleach will kill and decolorize mold, it does not remove mold. Dead mold can still cause allergic reactions. It is not necessary to kill mold to remove mold. Soap and water and scrubbing can remove mold from hard surfaces. The Environmental Protection Agency (EPA), the Center for Disease Control (CDC) and the New York City Health Department agree that bleach or other biocides should not routinely be used to clean up mold. See similar questions...