Severity of illness is a way to measure how bad someone is feeling when they are sick. When we get sick, our bodies don't work the way they normally do. This can cause us to feel tired, achy, and have other uncomfortable symptoms.
Think of it like a thermometer. When you have a fever, your temperature goes up and that tells you that you are not feeling well. Doctors use something similar to a thermometer to measure how severe someone's illness is. They ask questions and check different things like how high or low your temperature is, how fast your heart is beating, and how much pain you are in.
Based on all of these things, doctors can decide how serious your illness is and what kind of treatments you might need. For example, if you have a mild illness like a cold, you may only need to rest, drink plenty of fluids, and take over-the-counter medicine. But if you have a more severe illness like pneumonia, you may need to go to the hospital and receive stronger medicine or even oxygen therapy to help you breathe.
Overall, severity of illness is a way for doctors to figure out how sick you are and what they can do to help you feel better. The goal is to make you feel as comfortable as possible and help your body heal so you can get back to doing all the fun things you love to do!