Which of the following is NOT a typical component of a letter's introduction?

The introduction of a letter, especially in a healthcare context, typically serves to establish the key details about the patient and the purpose of the communication. Including the recipient's name helps to personalize the interaction and ensure that the letter reaches the correct individual. The patient's age and marital status are also relevant demographic details that can provide context for the recipient, particularly when discussing medical care or treatment decisions.

In this scenario, past medical history is not usually included in the introduction. Instead, it is typically part of the body of the letter where the patient's medical background is outlined in greater detail. This allows for a clearer and more succinct introduction that focuses on immediate relevant details rather than comprehensive background information. Therefore, it makes sense that past medical history is the component that does not belong in the introduction.