Allergies tend to flare up more in the morning than at night. Pollen levels are usually the highest around 5 a.m. and 10 a.m., so those with seasonal allergies may wake up with a stuffy nose or itchy eyes. However, allergies can be just as irritating at bedtime because allergens like dust can cling to your clothes, skin, and hair during the day. This can lead to a buildup of these allergens in your home, causing your symptoms to flare up at bedtime. For those with allergies, it is important to replace your mattress every 6 to 8 years. Mattresses collect dust, dirt, skin cells, and body oils over time, which can irritate your sinuses. Latex mattresses are also a great option for those with allergies because they are antimicrobial and antibacterial.