Why does my hair cause the pillow case to turn yellow?

Your hair can cause pillowcases to turn yellow due to a combination of natural oils, sweat, and product buildup from hair care products like shampoos, conditioners, and styling products. These substances can accumulate over time, leading to discoloration. Additionally, if you have lighter hair, especially blonde or gray, the oils and dirt may be more visible against the fabric. Regular washing of both your hair and pillowcases can help reduce this issue.