Clinical Features: Type 1 Diabetes

Presentation of Type 1 Diabetes
  • The ‘classic’ patient will show the following features:
    • More likely to be <40 y/o (although can affect at any age)
      • 2 peaks of presentation: one in preschool and one in teenagers
    • Acute onset  of symptoms developing over weeks/days
    • Long-term complications are unlikely at presentation in these patients due to the rapid onset of symptoms
    • Related autoimmune conditions (TAP CV)
      • Thyroid Disease (either hypo-thyroidism or hyper-thyroidism)
      • Addison Disease
      • Pernicious anaemia
      • Coeliac Disease
      • Vitiligo
  • T1DM patients typically present in one of three ways 
    1. Symptoms of hyperglycaemia
      • NB these are often more prominent in Type 1 patients due to the more acute onset making them more noticeable
    2. Symptoms of gluconeogenesis
    3. Acute decompensation (this is also due to gluconeogenesis)
      • DKA is the main presentation of acute decompensation in undiagnosed patients

Hyperglycaemic symptoms

  1. Increased systemic infection risk
    • These patients may present with boils
  2. Osmotic symptoms
    • Osmotic diuresis:
      • Polyuria + Nocturnal enuresis (nocturia)
      • Dehydration and polydipsia
      • Genital candidiasis and UTIs
      • Weight loss also occurs in part due to this
    • CNS symptoms
      • Blurred vision – develops as glucose enters into the lens and  pulls water in with it
      • Tiredness, fatigue, stupor and lethargy
      • Headache
      • Psychiatric – Mood changes and irritability


    • NB these are rare in T2DM
    1. Rapid weight loss
    2. Rapid muscle wasting
    3. DKA occurs with acute decompensation (See separate for more detail)
      • N&V and abdominal pain
      • Weakness and fatigue
      • Kussmaul respiration to blow off CO2 and compensate acidosis
      • Characteristic breath smell
      • Can ultimately lead to death