A 60-year-old man presents with fatigue, polyuria, and polydipsia. Laboratory tests reveal hyperglycemia and ketonuria. What is the most likely diagnosis?

Correct Answer: A

Rationale: The most likely diagnosis for a 60-year-old man with fatigue, polyuria, polydipsia, hyperglycemia, and ketonuria is Type 1 diabetes mellitus. The key clues are the presence of ketonuria, which indicates the body is breaking down fats for energy due to lack of insulin in Type 1 diabetes. Additionally, the acute onset of symptoms in an older individual suggests an autoimmune destruction of pancreatic beta cells seen in Type 1 diabetes. Type 2 diabetes is less likely due to the acute presentation and ketonuria. Diabetes insipidus presents with polyuria but not hyperglycemia or ketonuria. Hyperthyroidism typically presents with symptoms such as weight loss, tremors, and heat intolerance, not the classic symptoms seen in this case.

Correct Answer: A

Rationale: The correct answer is A: Hypothyroidism. In this scenario, the patient has symptoms of hypothyroidism (fatigue, weight gain, cold intolerance) along with high TSH and low free T4 levels, indicating primary hypothyroidism. TSH is elevated as the body is trying to stimulate the thyroid to produce more thyroid hormones. Free T4 is low as the thyroid is not able to produce enough hormones. Hyperthyroidism (choice B) would present with low TSH and high free T4 levels. Thyroiditis (choice C) typically presents with symptoms of hyperthyroidism followed by hypothyroidism. Thyroid cancer (choice D) usually does not cause these specific symptoms and lab findings. Therefore, based on the symptoms and lab results, hypothyroidism is the most likely diagnosis.

Correct Answer: A

Rationale: Step 1: Symptoms of fatigue, polyuria, polydipsia point to diabetes. Step 2: Hyperglycemia and ketonuria suggest uncontrolled diabetes. Step 3: Onset in a 30-year-old woman is more common in Type 1 diabetes. Step 4: Type 1 diabetes is characterized by autoimmune destruction of pancreatic beta cells leading to insulin deficiency. Step 5: Treatment for Type 1 diabetes involves insulin therapy. Summary: - Choice B (Type 2 diabetes) is less likely due to the acute presentation and ketonuria. - Choice C (Diabetes insipidus) does not involve hyperglycemia or ketonuria. - Choice D (Hyperthyroidism) does not typically present with hyperglycemia and ketonuria.

Correct Answer: B

Rationale: Rationale for Correct Answer B (Regurgitation of undigested food): 1. Esophageal diverticulum is a pouch-like protrusion in the esophageal wall, causing difficulty in swallowing. 2. Due to the diverticulum, food may get trapped and regurgitated, leading to regurgitation of undigested food. 3. This symptom is characteristic of esophageal diverticulum and indicates an abnormality in the esophageal functioning. Summary of Incorrect Choices: A: Burning pain on swallowing - Not a typical symptom of esophageal diverticulum; more indicative of conditions like GERD. C: Symptoms mimicking a myocardial infarction - Unrelated to esophageal diverticulum and more suggestive of cardiac issues. D: Chronic parotid abscesses - Not associated with esophageal diverticulum, as parotid abscesses involve the salivary glands.

Correct Answer: D

Rationale: The correct answer is D because inadequate nutrition and reduced saliva production contribute to cavities. In acute illness, the client may not be able to consume a balanced diet, leading to nutrient deficiencies that weaken teeth. Reduced saliva flow decreases the mouth's ability to naturally clean and protect teeth. Choices A, B, and C are incorrect because hormonal changes from stress do not directly lead to acidic oral environment, systemic infections do not commonly affect teeth, and lack of fluoride from intravenous hydration is not a primary factor for dental caries.