Final answer:
The symptoms may be related to grief-induced depression.
Step-by-step explanation:
The symptoms described by Don, including weight loss, fatigue, and difficulty sleeping, can be indicative of several medical conditions, including depression, anxiety, or a physical illness. Given that he recently lost his wife to breast cancer, it is important to consider the possibility of Don experiencing grief-related symptoms, such as depression or insomnia.
Depression can cause weight loss, fatigue, and difficulty sleeping. It is a common response to the loss of a loved one and can manifest in physical symptoms. It is recommended for Don to seek support from a mental health professional who can provide appropriate guidance and support during this challenging time.