Dr. Greene's Answer
You may feel like this only happens to your child, but you are not alone! This happens to everyone, no matter what the age. There are three primary reasons for this. First, the pressures in our bodies change when we are horizontal. Lying down increases congestion, ear pain, postnasal drip, sore throats, and several types of cough.
Additionally, our bodies are on a 24 hour clock called the Circadian Rhythm. Hormone levels rise and fall according to this daily cycle. Some hormones help us to wake up in the morning, others help us to sleep at night. These same hormones affect how we feel pain. During the day high levels of cortisol, a stress hormone, keep us from feeling some of the pain and keep our fevers in check. At night our fevers rise and our discomfort increases. As if this weren’t enough, throughout the day our senses are barraged by gigabytes of stimuli every second, and our brains are busy processing all the data. At night the amount of stimuli we are bombarded with is drastically reduced. This gives our brains an opportunity to pay more attention to this already increased level of pain. These factors combine to greatly amplify symptoms at night. Feeling better in the morning doesn’t mean that you are better.
Obviously there are times that your child is so sick at night that you will need to call your pediatrician for immediate care. If your son is sick at night, but not sick enough to require urgent medical care, it is still appropriate to take him to the pediatrician in the morning, even if your child appears better. A good rule of thumb is, if you wouldn’t want your son (or yourself) to have another night like the last one, then it is time to consult your pediatrician.