Diabetes is a syndrome characterized by disordered metabolism and inappropriately high blood sugar (hyperglycaemia) resulting from either low levels of the hormone insulin or from abnormal resistance to insulin's effects coupled with inadequate levels of insulin secretion to compensate.

SYMPTOMS OF HYPERGLYCAEMIA

• Thirst, dry mouth
• Polyuria
• Nocturia
• Tiredness, fatigue
• Recent change in weight
• Blurring of vision
• Pruritus vulvae, balanitis (genital candidiasis)
• Nausea; headache
• Hyperphagia; predilection for sweet foods
• Mood change, irritability, difficulty in concentrating, apathy

COMPARATIVE CLINICAL FEATURES OF TYPE 1 AND TYPE 2 DIABETES

Typical age at onset	< 40 years	> 50 years
Duration of symptoms years	Weeks	Months to
Body weight	Normal or low	Obese
Ketonuria	Yes	No
Rapid death without treatment with insulin	Yes	No
Autoantibodies	Yes	No
Diabetic complications at diagnosis	No	25%
Family history of diabetes	Uncommon	Common
Other autoimmune disease	Common	Uncommon