Before applying enhancements, assessing the natural nail's health is important to:

Assessing the natural nail's health before applying enhancements is important so the cosmetologist avoids applying products over infected, diseased, or significantly damaged nails — which could trap and worsen a problem or produce a poor, unsafe result. Enhancements should go only on healthy nails, and any signs of infection or disorder warrant declining the service and referring the client. This analysis-first, health-aware approach mirrors the rest of the curriculum and is reinforced in the nail-enhancement content of the exam.