Vital signs are a collection of determinants doctors use to find out if your body's vital (most important) functions are within the norm. These are helpful in diagnosing any illnesses or diseases because at least one of your vital signs will show anomalies when you are sick. Also, the standard for vital signs varies with age, weight, and gender of a person. The 4 main vital signs include: body temperature, blood pressure, pulse, and respiratory rate.