The answer to 'bathroom mildew' is that mildew is a type of fungus that commonly grows in moist, humid environments like bathrooms. Symptoms include black, green, or white fuzzy growth on surfaces like tiles, caulk, and grout. Common causes are poor ventilation, leaks, and high humidity levels.
For minor mildew, you can often treat it yourself using a bathroom cleaner with bleach or a vinegar solution. However, for more extensive mildew growth or recurring issues, it's best to call a professional cleaning service. They have the expertise and equipment to properly identify and remove mildew, as well as address any underlying moisture problems in your bathroom.