tl;dr - mold usually only significantly affects people prone to respiratory infections or allergies. it's a lung irritant for most people but once the mold is

tl;dr - mold usually only significantly affects people prone to respiratory infections or allergies. it's a lung irritant for most people but once the mold is removed, the lungs typically recover. when remediating mold, it's a good idea to have a respirator and eye mask, mostly just to prevent irritation or from breathing cleaning chemicals - you can never stop mold from being in your house, but you can prevent it from growing. mold grows faster the hotter it is, and typically grows at 55% humidity or higher. reduce humidity and stop any dripping or standing water to prevent mold growth. to reduce humidity you can use a dehumidifier or desiccants (better for closets/drawers). increased air flow also helps prevent mold (mold likes dark places without air flow and high humidity) - mold can be found in most central air systems/vents, it's not surprising. but it will grow and cause health issues if the air conditioning system is prone to water or high humidity. - the reason you need to remove mold even if you don't smell it/it's not visible is mold breaks down organic matter, so it will stain and/or destroy clothes, wood, leather, etc. - different molds have different behaviors. some can be killed with just vinegar, but some need a more severe treatment. bleach, other household products don't tend to work, because it doesn't kill the root. - once a mold root gains hold in a permeable material, it's pretty hard to kill the root, so you can kill the outer version of it but it'll often just grow back. so if flooring/sheathing like OSB gets mold, you'll probably need to scrap it. hard wood can take longer for mold to grow on but once the roots are in the wood, you'd need to remove the wood down to the root or it'll grow back. - concrobium mold control is the best overall product for mold control, as it can kill the mold and root and prevent mold from regrowing on surfaces. if you find mold in hard to reach areas, a dry fogger with concrobium is often the easiest solution - if it's not practical for you to reduce humidity or increase airflow in a given space, keep your stuff in airtight plastic bins.