My 18-month-old's nose constantly runs since starting daycare: is it normal?

An 18-month-old constantly getting sick and having a runny nose after starting daycare is what pediatrics calls "daycare adaptation syndrome" — extremely common. Growing up in a limited microbial environment, young children suddenly encounter dozens of different viruses at daycare. While their immune system learns to recognize each new virus, upper respiratory infections (colds, runny nose) become unavoidable. Getting 6–8 infections a month, especially in winter, is considered normal in the first daycare year. This period typically improves significantly within 6–12 months. What matters is: if fever lasts over 3 days, ear pain (coughing, fussiness, sleep disruption), wheezing, or yellow-green eye discharge appear, these could be more than a simple cold and need pediatric evaluation. If the runny nose is clear, there's no fever, and baby generally seems well, supporting at home with saline drops and plenty of fluids is enough. Though this adjustment period is exhausting, it's a natural training ground for your child's immune system.