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Making things worse is the fact that mold is capable of growing in tight places. This allows for the mold to build up at a faster rate. This means that mold can thrive in the cracks between tiles and underneath the sink. It can become very overwhelming very quickly. If you want to prevent mold from spreading in your bathroom then the first thing you need to do is make sure to properly ventilate your bathroom. If there is not proper airflow then you are helping to keep your bathroom at a warm temperature and it will just become a moisture trap. Make a point to leave your bathroom door open after you have taken a shower so that the excess steam and heat can dissipate and the bathroom can return to a normal temperature. http://www.thehayloftonline.com/understanding-bathroom-mold/