As you’ve probably guessed, sweat is the main and most likely cause. Your pillow will gradually and irreversibly yellow each night. Sweat dripping from your body penetrates the pillow’s fibers before rising to the surface. However, while sweat remains the most likely cause, other factors, such as saliva, also play a role.
The bodily fluids we excrete contribute to the yellowing of the pillow that absorbs them. Furthermore, this discoloration isn’t just an aesthetic problem—it’s a sign that bacteria and dust mites have taken up residence in the fibers. And it’s precisely in such environments that these parasites love to settle, which can trigger ailments like asthma or troublesome rhinitis.
