Differential Diagnoses

Differential Diagnosis I

Diabetes mellitus type 2 is an ailment involving hyperglycemia and insulin resistance.

Rationale: The patient is presenting with fatigue and weight loss which may be indicative of diabetes mellitus type 2, and his blood glucose is abnormally high.  Classic symptoms for diabetes mellitus type 2 include: Polyuria, polydipsia, polyphagia, blurred vision, fatigue and weight loss. Other presentations include: Lower-extremity paresthesias, yeast infections in females, balanitis in males and slow-healing wounds.

Diagnosis of diabetes mellitus includes any of the following:

  • A glycosolated hemoglobin, or hemoglobin A1C, greater than or equal to 6.5%, or
  • Fasting plasma glucose (FPG) level of 126 mg/dL (7.0 mmol/L) or higher, or
  •  2-hour plasma glucose level of 200 mg/dL (11.1 mmol/L) or higher during a 75-g oral glucose tolerance test (OGTT), or
  • A random plasma glucose of 200 mg/dL (11.1 mmol/L) or higher in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis

From McCance and Huether (2014).


Differential Diagnosis II

Metabolic syndrome is a group of risk factors thought to be linked to insulin resistance. It can occur in patients with normal glucose tolerance, prediabetes, and diabetes.

Rationale: The patient’s presentation could be indicative of metabolic syndrome.

Metabolic Syndrome is diagnosed when 3 of 5 conditions exist

  • Abdominal obesity
  • Elevated triglyceride level
  • Low level of high-density lipoprotein (HDL) cholesterol
  • Elevated blood pressure
  • Fasting glucose value of 100 mg/dL or higher

From McCance and Huether (2014).


Differential Diagnosis III

Hyperthyroidism  is over activity of the thyroid gland as a result of an overproduction  of thyroxine.

Rationale: Weight loss and fatigue could be indicative of hyperthyroidism.  Classic symptoms: Excessive sweating, weight loss, tachycardia, hand tremors, anxiety, fatigue, muscle weakness and insomnia

  • Thyroid function tests confirm the diagnosis
  • The presence of autoantibodies rule out hyperthyroid
  • Thyroid imaging rules out other causes, such as nodules, inflammation or overactivity

From McCance and Huether (2014).

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