Type 1 diabetes is an autoimmune disease in which the body destroys the insulin-making beta cells of the pancreas, so lifelong insulin is needed. It often starts in childhood or young adulthood, and without insulin it leads to diabetic ketoacidosis (DKA).
Key symptoms
- Excess thirst and frequent urination, including new bedwetting in children
- Weight loss despite eating well
- Fatigue and blurred vision
- Nausea, vomiting and abdominal pain if DKA develops
What you find on exam
- Signs of dehydration: dry mouth, fast pulse
- Deep, rapid breathing (Kussmaul) and fruity breath in DKA
- Mental status and vital signs
- At follow-up: injection sites, feet, blood pressure and growth in children
Tests
- Plasma glucose: fasting 126 mg/dL or more, or random 200 mg/dL or more with symptoms
- HbA1c of 6.5 percent or more
- Ketones in blood or urine; blood gas and anion gap if unwell
- Autoantibodies (GAD65, IA-2, ZnT8) and C-peptide to confirm type 1
- Screen for celiac and thyroid disease
Treatment basics
- Basal-bolus insulin: long-acting glargine plus rapid-acting lispro or aspart with meals
- Insulin pump and continuous glucose monitor when available
- Carbohydrate counting, sick-day rules and hypoglycemia teaching, with glucagon at home
- HbA1c target under 7 percent for most patients
- Yearly eye, kidney, foot and lipid checks
Red flags
- Vomiting, abdominal pain or deep breathing with high glucose (DKA)
- Confusion, seizure or unresponsiveness from low glucose
- Ketones that stay high despite extra insulin during illness
Practice it in Making Synapses
Making Synapses cases
Related guides
Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.