Version July 2025
| Symptoms, signs, or both | Glucose (mg/dL)/(mmol/L) | Insulin (microU/mL)/(pmol/L) | C-peptide (nmol/L)/(ng/mL) | Proinsulin (pmol/L) | Beta-hydroxybutyrate (mmol/L) | Glucose increase after glucagon (mg/dL)/(mmol/L) | Circulating oral hypoglycemic agent | Antibody to insulin | Diagnostic interpretation |
| No | <55/3 | <3/20.8 | <0.2/0.6 | <5 | >2.7 | <25/1.4 | No | No | Normal |
| Yes | <55 | >>3 | <0.2 | <5 | ≤2.7 | >25 | No | Neg (Pos) | Exogenous insulin |
| Yes | <55 | ≥3 | ≥0.2 | ≥5 | ≤2.7 | >25 | No | Neg | Insulinoma, NIPHS, PGBH |
| Yes | <55 | ≥3 | ≥0.2 | ≥5 | ≤2.7 | >25 | Yes | Neg | Oral hypoglycemic agent |
| Yes | <55 | >>3 | >>0.2¶ | >>5¶ | ≤2.7 | >25 | No | Pos | Insulin autoimmune |
| Yes | <55 | <3 | <0.2 | <5 | ≤2.7 | >25 | No | Neg | IGFΔ |
| Yes | <55 | <3 | <0.2 | <5 | >2.7 | <25 | No | Neg | Not insulin (or IGF)-mediated |
IGF: insulin-like growth factor; Neg: negative; NIPHS: noninsulinoma pancreatogenous hypoglycemia syndrome; PGBH: post-gastric bypass hypoglycemia; Pos: positive.
* Patterns of findings during fasting or after a mixed meal in healthy individuals with no symptoms or signs despite relatively low plasma glucose concentrations (ie, Whipple's triad not documented) and in individuals with hyperinsulinemic (or IGF-mediated) hypoglycemia or hypoglycemia caused by other mechanisms.
¶ Free C-peptide and proinsulin concentrations are low.
Δ Increased pro-IGF-2, free IGF-2, IGF-2/IGF-1 ratio.