The answer to 'my hardwood floor is filthy' is that there are several common causes for a dirty hardwood floor, including heavy foot traffic, pet messes, spills, and lack of regular cleaning. Symptoms may include a dull, discolored appearance, sticky or gritty texture, and visible dirt or debris. To solve this problem, you'll need to thoroughly clean and restore the floor.
For a light cleaning, you can try sweeping, vacuuming, and mopping the floor with a hardwood floor cleaner. However, if the floor is heavily soiled or damaged, you may need to sand and refinish it. This is a more intensive process that is best handled by a professional hardwood floor cleaning and restoration service.