• thirst: due to the resulting loss of fluid
• weight loss: due to fluid depletion and breakdown of fat
and muscle secondary to insulin deficiency.
Other common symptoms are tiredness, mood changes and
blurred vision (due to glucose-induced changes in lens refraction).
Bacterial and fungal skin infections are common because of the
combination of hyperglycaemia, impaired immune resistance
and tissue ischaemia. Itching of the genitalia (pruritus vulvae in
women, balanitis in men) is due to Candida yeast infection (thrush).
Past medical, drug, family and
• Previous glucose intolerance or gestational diabetes, which
are risk factors for progression to type 2 diabetes.
• Other autoimmune conditions such as thyroid disease
(increased incidence of type 1 diabetes).
• Drug therapy: glucocorticoids can cause steroid-induced
• Family history of diabetes or autoimmune disease.
Monogenic diabetes is usually inherited in an autosomal
dominant manner. Patients are often slim (unlike those with
type 2 diabetes) but do not require insulin at diagnosis (unlike
those with type 1 diabetes). Monogenic diabetes should be
considered in people presenting with diabetes under the age
of 30 who have an affected parent or a family history of
early-onset diabetes in around 50% of first-degree relatives.
• Smoking habit: combines with diabetes to increase the
risk of vascular complications.
• Alcohol: raises the possibility of pancreatic diabetes.
Fig. 10.13 Klinefelter’s syndrome. Tall stature, gynaecomastia, reduced
The pancreas lies behind the stomach on the posterior abdominal
wall. Its endocrine functions include production of insulin (from beta
cells), glucagon, gastrin and somatostatin. Its exocrine function
is to produce alkaline secretions containing digestive enzymes.
Diabetes mellitus is characterised by hyperglycaemia caused
by absolute or relative insulin deficiency.
Diabetes may be primary or secondary. Primary diabetes is
• type 1: severe insulin deficiency due to autoimmune
destruction of the pancreatic islets. These patients are
susceptible to acute decompensation due to hypoglycaemia
or ketoacidosis, both of which require prompt treatment.
• type 2: commonly affects people who are obese and
insulin-resistant, although impaired beta-cell function is
also important. These patients may decompensate by
developing a hyperosmolar hyperglycaemic state.
Secondary causes of diabetes and the associated history and
examination features are described in Box 10.5.
Diabetes mellitus commonly presents with a classical triad of
• polyuria (and nocturia): due to osmotic diuresis caused by
Assessment of a patient with newly
• Look for evidence of weight loss and dehydration.
Unintentional weight loss is suggestive of insulin deficiency.
• Check for clinical features of acromegaly or Cushing’s
• Look for Kussmaul respiration (hyperventilation with a
deep, sighing respiratory pattern) or the sweet smell of
ketones, both of which suggest insulin deficiency and
• Skin: look for signs of infection such as cellulitis, boils,
abscesses and fungal infections, paying particular attention
to the feet (see later). Look for signs of insulin resistance
such as acanthosis nigricans (Fig. 10.15A). Necrobiosis
lipoidica, a yellow, indurated or ulcerated area surrounded
by a red margin indicating collagen degeneration (Fig.
10.15B), may occur on the shins in type 1 diabetes and
often causes chronic ulceration.
• Look for xanthelasmata and xanthomata (Fig. 10.15C; see
Fig. 4.6); these are suggestive of dyslipidaemia, which may
• Measure the pulse and blood pressure, and examine the
cardiovascular and peripheral vascular systems, with a
particular emphasis on arterial pulses in the feet (p. 69).
• Examine the central nervous system, with a particular
focus on sensation in the lower limbs (p. 143).
• Test visual acuity and perform fundoscopy (p. 164; see
• Perform urinalysis for glycosuria.
Microvascular, neuropathic and macrovascular complications
of hyperglycaemia can occur in patients with any type of diabetes
mellitus, and may be present at diagnosis in patients with
Glycosuria is in keeping with diabetes; the presence of urinary
(or blood) ketones suggests insulin deficiency and the possibility
of diabetic ketoacidosis. Other investigations to consider are
In established diabetes, vital aspects of the history (Box
10.6) and examination should be reviewed at least once
The physical examination will differ, depending on whether this
is a new presentation of diabetes or a patient with established
diabetes attending for their annual review.
10.6 Routine history taking as part of the annual
• Ask about frequency of blood glucose testing and frequency and
awareness of symptoms of hypoglycaemia
• When relevant, give guidance on driving and/or pre-pregnancy
• Enquire about any lumpiness (lipohypertrophy), bruising or
Symptoms of macrovascular disease
• Ask whether there has been any angina, myocardial infarction,
claudication, stroke or transient ischaemic attack since the last
Symptoms of microvascular disease
• Ask whether there has been any change in vision or any numbness
or altered sensation in the feet
• Ask about neuropathy and peripheral vascular symptoms as above
• Enquire about any breaks in the skin, infections or ulcers
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