How often should you replace a pillow?

Most pillows need replacing every 1 to 2 years, sooner than people expect. Over time they collect dust mites, skin cells, oils, and moisture, and the fill breaks down so it no longer supports the neck. A simple test: fold the pillow in half, and if it stays folded instead of springing back, it is done. Waking with neck aches or persistent congestion is another sign it is time.