A patient with a history of hypertension presents with a severe headache, confusion, and visual disturbances. His blood pressure is 220/120 mm Hg. Which of the following is the most likely diagnosis?

Correct Answer: C

Rationale: A patient with a history of hypertension presenting with a severe headache, confusion, and visual disturbances, along with a blood pressure of 220/120 mm Hg, likely has a hypertensive emergency. In this situation, the severely elevated blood pressure can lead to end-organ damage, causing symptoms such as headache and confusion. Migraine and tension headaches are not associated with such high blood pressure levels. Cluster headaches typically do not present with visual disturbances and confusion in the setting of severe hypertension.

Correct Answer: A

Rationale: A positive Homan's sign is indicative of deep vein thrombosis. This sign is elicited by dorsiflexing the foot of a patient with the knee slightly flexed, resulting in calf pain. Peripheral artery disease (choice B) is associated with decreased blood flow to the extremities, but it does not produce a positive Homan's sign. Varicose veins (choice C) are enlarged, twisted veins that are typically not related to Homan's sign. Lymphedema (choice D) is swelling caused by a lymphatic system blockage or dysfunction and is not linked to Homan's sign.

Correct Answer: B

Rationale: The scenario describes a 45-year-old woman with fatigue, weight gain, cold intolerance, low T3 and T4 levels, and elevated TSH levels, which are indicative of hypothyroidism. In hypothyroidism, there is decreased production of thyroid hormones (T3 and T4) leading to elevated TSH levels as the pituitary gland tries to stimulate the thyroid gland to produce more hormones. Therefore, the correct answer is hypothyroidism (Choice B). Choice A, Hyperthyroidism, is incorrect as the patient's symptoms and thyroid function tests point towards decreased thyroid hormone levels, which is characteristic of hypothyroidism, not hyperthyroidism. Choice C, Euthyroid sick syndrome, is incorrect because this condition typically presents with normal to low T3 and T4 levels in the setting of non-thyroid illness, unlike the elevated TSH levels observed in this case. Choice D, Subclinical hyperthyroidism, is also incorrect as the patient has low T3 and T4 levels, which is not consistent with hyperthyroidism, whether clinical or subclinical.

Correct Answer: A

Rationale: Primary aldosteronism is a common cause of secondary hypertension. In primary aldosteronism, there is an overproduction of aldosterone from the adrenal glands, leading to increased sodium retention and potassium excretion, ultimately resulting in high blood pressure. Essential hypertension (Choice B) is the most common type of hypertension, but it is considered primary hypertension, not secondary. White coat hypertension (Choice C) refers to elevated blood pressure readings in a clinical setting due to anxiety but not in daily life. Prehypertension (Choice D) is a condition where blood pressure levels are elevated but not high enough to be classified as hypertension.

Correct Answer: C

Rationale: In a 60-year-old man presenting with painless hematuria, the next step in the evaluation should be cystoscopy. Cystoscopy is recommended to assess the cause of hematuria, particularly to rule out bladder cancer, which is more common in older individuals. Urinalysis (Choice A) can provide initial information but may not definitively diagnose the underlying cause. Renal ultrasound (Choice B) and intravenous pyelogram (Choice D) are imaging studies that may be considered later in the evaluation process but are not the initial step for painless hematuria.