Final answer:
Patients who indicate they are allergic to Novocain are experiencing adverse reactions or hypersensitivity to the local anesthetic, which can range from mild to severe symptoms. It's important to inform healthcare professionals about this allergy to prevent complications during medical or dental procedures.
Step-by-step explanation:
When a patient indicates they are "allergic to Novocain", it typically means that they are experiencing adverse reactions or hypersensitivity to the local anesthetic called Novocain, which contains procaine as a key component. These reactions can range from mild symptoms like itching or swelling to more severe reactions like difficulty breathing or anaphylaxis. It's important for patients to inform healthcare professionals about their allergy to Novocain to avoid potential complications during medical or dental procedures.