Final answer:
Burns are classified by their (A) depth (degree) and extent (total surface area), applying measures like the "rule of nines" to estimate affected areas. Treatments vary based on severity, from self-healing of first-degree burns to medical procedures like grafting for third- and fourth-degree burns.
Step-by-step explanation:
Burns are classified according to their depth and extent. There are four primary degrees of burns, each with increasing severity. First-degree burns affect only the epidermis and may cause pain and swelling, and usually heal on their own. Second-degree burns involve both the epidermis and a portion of the dermis, leading to swelling and blisters. Third-degree burns extend through the dermis, destroying tissue and affecting nerves, and require medical attention. Fourth-degree burns are the most severe, affecting muscle and bone and often damaging nerve endings, thus sometimes not feeling as painful.
To measure the extent of a burn, the "rule of nines" is often used, assigning percentages to sections of the body to estimate the total body surface area affected. The severity of a burn influences treatment, which can range from simple cleaning and dressing of the wound for minor burns to intravenous fluids, debridement, and skin grafting for more serious burns.