The general expert recommendation is to change and wash bed sheets about once a week. Washing sheets weekly helps remove bacteria, dead skin cells, sweat, oils, dust mites, and other allergens, contributing to healthier skin and better sleep hygiene. If you have allergies, asthma, sweat a lot at night, or let pets sleep in your bed, more frequent washing (e.g., multiple times per week) is advisable. Pillowcases should also be changed weekly. Other bedding like duvet covers or comforters can be washed less often, such as every few weeks to months depending on use. Key points:

• Change sheets once a week for hygiene and comfort.
• Change more often if sweating heavily, sick, or sharing bed with pets/children.
• Pillowcases should be washed weekly.
• Duvet covers and comforters can be washed every few months.
• Washing sheets promptly after use and ensuring they are completely dry before reuse is important.
• Showering before bed and keeping pets off the bed can help keep sheets cleaner longer.

This guidance is consistent across multiple expert sources and studies from 2023-2025 and applies in all seasons.