Mold and Mildew Growth
Brown spots that appear on your bathroom's ceiling after you finish taking a shower are possibly signs of mold or mildew growth in the bathroom. Both mold and mildew require moisture to grow, making the bathroom a good location for growth. Showering increases the humidity in the bathroom, causing water to condense on the ceiling. If the ceiling stays damp, mold and mildew can grow in that location.
Preventing Mold Growth
Preventing mold growth provides the best long-term solution to the problem, since prevention requires less effort than removing the mold. Keeping the humidity and moisture levels in the bathroom low will help with prevention, meaning you should open the bathroom window and run the fan after you take showers or baths. If you see water condensing on the ceiling in the bathroom, wipe it off immediately until the ceiling is dry.
As mold grows, it releases tiny spores into the air in an effort to spread mold growth throughout your house. You inadvertently breathe these tiny spores in as they travel through the air. Some people develop an allergic reaction to mold spores, causing them to experience cold or flulike symptoms. In serious cases, a person can experience an asthma attack from mold exposure, develop a lung infection, experience a fungal growth in the nasal cavity or experience bleeding in the lungs. Children, people with weakened immune systems and people with respiratory problems are at the greatest risk of adverse effects from mold exposure.
Always wear protective gear when removing mold, such as eye goggles, rubber gloves and clothing that covers your skin. Do not run the air conditioning or heater while cleaning mold to keep the spores from getting blown around. You must wet mold down before you begin cleaning it; spray it with a bottle sprayer filled with a mixture of bleach and water. Leaving the site of the mold growth wet after cleaning it may result in the mold coming back. If the mold continues to come back, you may need to remove the drywall since it is a porous material and that house moisture and mold.