The answer to 'why is my hardwood floor stained' is that there are several common causes, including spills, pet accidents, water damage, and excessive wear. Stains can range from light discoloration to deep, dark spots depending on the type and severity of the issue.
Some of the most common causes of hardwood floor stains include food and drink spills, pet urine, standing water from leaks or floods, and excessive foot traffic wearing down the finish. Over time, these can all lead to unsightly stains and discoloration on the wood.