Skip to Main Content

Probability diagnosis

Exogenous obesity

Alcohol excess



Genetic polymorphisms

Serious disorders not to be missed


  • cardiac failure

Hypothalamic disorders (hyperphagia):

  • craniopharyngiomas

  • optic gliomas


Liver failure

Nephrotic syndrome

Pitfalls (often missed)

Pregnancy (early)


Endocrine disorders:

  • hypothyroidism

  • Cushing syndrome

  • insulinoma

  • acromegaly

  • hypogonadism

  • hyperprolactinaemia

  • polycystic ovarian disease

Idiopathic oedema syndrome

Klinefelter syndrome

Congenital disorders:

  • Prader–Willi syndrome

  • Laurence–Moon–Biedl syndrome

Masquerades checklist


Drugs (e.g. OCP, steroids, pizotifen, sulphonylureas, insulin)

Thyroid disorder (hypothyroidism) and other endocrine (as above)

Is the patient trying to tell me something?

Yes: the reasons for obesity should be explored.

Key history

Ascertain food and beverage intake including typical daily meals. Exercise, drug, psychological and family history.

Key examination

  • Measure body weight and height and calculate BMI, waist circumference, waist–hip circumference, upper arm circumference

  • Assess the degree and distribution of body fat and the overall nutritional status

  • Search for evidence of diabetes, atherosclerosis, hypothyroidism, Cushing syndrome and signs of alcohol abuse

Key investigations

These are more appropriate if patient unwell:

  • anthropometric measurements as above, especially BMI and waist circumference

  • FBE

  • blood lipids

  • glucose (fasting)

  • LFTs

  • U&E

Consider TFTs, serum cortisol, ECG and CXR.

Diagnostic tips

  • The onset of obesity can occur at any age.

  • Abdominal obesity gives a higher cardiovascular risk at any rate.

  • Ask the patient what they believe is the cause of their weight gain/obesity.

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.