Classic Symptoms of Diabetes Mellitus
Polyphagia (increased hunger) is NOT consistently listed as a classic symptom of diabetes mellitus in the major diagnostic guidelines, while polyuria, polydipsia, and unexplained weight loss are universally recognized as the hallmark clinical features.
The Three Classic Symptoms
The American Diabetes Association consistently identifies three classic symptoms across multiple iterations of their Standards of Care:
- Polyuria (excessive urination) - occurs due to osmotic diuresis when blood glucose exceeds the renal threshold 1
- Polydipsia (excessive thirst) - develops as a compensatory mechanism for fluid losses from polyuria 1
- Unexplained weight loss - results from inability to utilize glucose for energy, leading to breakdown of fat and muscle tissue 1, 2
Why Polyphagia Is Not Consistently Included
While polyphagia (increased hunger) may occur in some patients with diabetes, it is not listed among the classic diagnostic symptoms in the most authoritative guidelines:
- The 2025 ADA Standards of Care specifically state that random plasma glucose ≥200 mg/dL accompanied by "classic hyperglycemic symptoms (e.g., polyuria, polydipsia, and unexplained weight loss)" is sufficient for diagnosis 1
- The 2008 ADA Standards similarly define "classic symptoms of hyperglycemia include polyuria, polydipsia, and unexplained weight loss" 1
- The 2005 ADA diagnostic criteria list only these three symptoms as classic features 1
Clinical Context
Children with type 1 diabetes typically present with polyuria and polydipsia as hallmark symptoms, with approximately half also presenting with diabetic ketoacidosis 1. The triad of polyuria, polydipsia, and weight loss represents the most reliable clinical presentation that, when combined with random glucose ≥200 mg/dL, allows for immediate diagnosis without need for confirmatory testing 1.
Common Pitfall
A critical caveat: while polyphagia may be present in some diabetic patients (particularly early in type 2 diabetes when insulin levels are still elevated but ineffective), it is not specific enough to be considered a classic diagnostic symptom and should not be relied upon for clinical diagnosis 1.
Answer: B. Polyphagia