Final answer:
A 78-year-old female showing symptoms of memory loss and cognitive decline may be assessed for mild Alzheimer's disease through a comprehensive medical work-up, including physical exams, cognitive tests, interviews, and a brain scan.
Step-by-step explanation:
The diagnosis for a 78-year-old female presenting with memory loss and a sudden, step-wise decrease in memory and cognitions should consider the possibility of mild Alzheimer's disease (AD). Given her symptoms, which include trouble with paying bills, managing a budget, and increased irritability, alongside getting disoriented in a familiar place, a thorough medical work-up is necessary. This would involve a complete physical exam, laboratory tests, an in-depth interview about her memory and mood changes, cognitive tests to assess problem-solving abilities, and a brain scan to rule out other causes like tumors. Her symptoms are consistent with the main symptoms of Alzheimer's, which include disruptive memory loss, confusion, difficulty with tasks, and personality changes.