PACES PATHFINDERS LEARNING LIBRARY

Hypopituitarism (Fatigue Approach)

Fatigue • Amenorrhoea • Pituitary Failure • MRCP (UK) PACES

A structured MRCP (UK) PACES approach to patients presenting with chronic fatigue caused by pituitary hormone deficiency. Learn how to recognise hypopituitarism, identify pituitary tumours, investigate hormone deficiencies and counsel patients confidently during the Long Clinical Consultation station.

15 min read Long Clinical Consultation Very High Yield

At a Glance

Presentation Fatigue

Likely Diagnosis Hypopituitarism

Important Symptom Amenorrhoea

Must Not Miss Pituitary Mass

Key Investigation Pituitary Hormone Profile + MRI

Common Cause Pituitary Adenoma

Red Flags

Visual field defect Persistent headache Amenorrhoea Hypotension Loss of body hair Pituitary apoplexy Postpartum haemorrhage Adrenal crisis

PACES Approach

① Assess fatigue ② Identify pituitary hormone deficiency ③ Look for pituitary mass effects ④ Confirm endocrine diagnosis ⑤ Replace deficient hormones safely

Pituitary Hormone Deficiencies

ACTH
Fatigue • Hypotension

TSH
Secondary hypothyroidism

LH / FSH
Amenorrhoea • Infertility

Growth Hormone
Reduced muscle mass • Low energy

Prolactin
Failure to lactate

Mass Effect
Headache • Bitemporal hemianopia

Overview

Hypopituitarism is characterised by partial or complete deficiency of one or more pituitary hormones. Patients commonly present with fatigue, reduced exercise tolerance, amenorrhoea, infertility or loss of secondary sexual characteristics. During the MRCP (UK) PACES Long Clinical Consultation, candidates should recognise features of pituitary hormone deficiency, assess for mass effects such as headache and bitemporal hemianopia, and identify potentially life-threatening ACTH deficiency requiring urgent treatment. :contentReference[oaicite:1]{index=1}

Focused History

Assess the Fatigue

When did the fatigue begin?
Was the onset sudden or gradual?
Has it remained stable or progressively worsened?
How does it affect daily activities and work?
Does rest improve the symptoms?
Any associated weight change?

Symptoms Suggesting Pituitary Disease

Persistent headache.
Blurred vision or reduced peripheral vision.
Amenorrhoea or irregular menstrual periods.
Reduced libido.
Infertility.
Loss of facial, axillary or pubic hair.
Reduced muscle strength.

Screen for Individual Hormone Deficiencies

Cold intolerance and constipation (TSH deficiency).
Postural dizziness or recurrent collapse (ACTH deficiency).
Reduced exercise capacity and loss of muscle mass (GH deficiency).
Failure to lactate after childbirth (prolactin deficiency).
Hot flushes and amenorrhoea (gonadotrophin deficiency).

Identify Possible Causes

Previous pituitary surgery.
Radiotherapy to the head.
Significant postpartum haemorrhage (Sheehan syndrome).
Head injury.
Known pituitary tumour.
Autoimmune or infiltrative disease.
Previous pituitary apoplexy.

Exclude Other Causes of Fatigue

Anaemia.
Primary hypothyroidism.
Addison disease.
Depression.
Chronic infection.
Malignancy.

Drug, Family and Social History

Current medications.
Glucocorticoid use.
Family history of endocrine disorders.
Smoking and alcohol intake.
Impact on work and quality of life.

Focused Examination

Assess general appearance and body habitus.
Look for pallor and characteristic pale, dry "alabaster" skin.
Measure lying and standing blood pressure.
Assess visual fields for bitemporal hemianopia.
Perform fundoscopy.
Palpate the thyroid gland.
Assess secondary sexual characteristics.
Look for loss of axillary or pubic hair.
Assess muscle bulk and proximal muscle strength.
Look for features suggesting alternative endocrine disorders.

Differential Diagnosis

Hypopituitarism Primary Hypothyroidism Primary Adrenal Insufficiency Anaemia Chronic Fatigue Syndrome Depression Pituitary Adenoma Systemic Malignancy Multiple Sclerosis

Investigations

Baseline Investigations

Full blood count.
Urea, electrolytes and creatinine.
Liver function tests.
Inflammatory markers.
Blood glucose.

Pituitary Hormone Profile

Morning serum cortisol.
Free T4 and TSH.
LH and FSH.
Oestradiol (women) or testosterone (men).
Prolactin.
IGF-1.

Imaging

MRI pituitary with contrast (preferred).
CT brain if MRI is unavailable or contraindicated.
Formal visual field assessment if a pituitary mass is suspected.

PACES Tip: Suspected ACTH deficiency should be recognised promptly. Glucocorticoid replacement should be initiated before starting thyroid hormone replacement if adrenal insufficiency has not been excluded, to avoid precipitating adrenal crisis. :contentReference[oaicite:1]{index=1}

Diagnosis

Hypopituitarism

The combination of chronic fatigue, amenorrhoea or hypogonadism, symptoms of multiple pituitary hormone deficiencies and possible mass effects such as headache or bitemporal hemianopia strongly suggests hypopituitarism. Confirmation requires pituitary hormone assessment together with pituitary MRI to identify the underlying cause. :contentReference[oaicite:2]{index=2}

Explaining to the Patient

"From your symptoms and examination, I am concerned that your pituitary gland—the small gland at the base of the brain that controls many of the body's hormones—is not producing enough hormones. This can explain your tiredness and changes in your menstrual cycle. We need to perform specialised blood tests and a scan of the pituitary gland to confirm the diagnosis and determine the underlying cause. Once identified, hormone replacement treatment is usually very effective."

Management

Treat Hormone Deficiencies Replace deficient hormones individually. Always replace glucocorticoids before commencing thyroid hormone if ACTH deficiency has not been excluded.

Treat the Underlying Cause Manage pituitary adenomas, infiltrative disease, pituitary apoplexy or other structural lesions in collaboration with endocrinology and neurosurgery.

Monitor Long-term Regular endocrine review, repeat pituitary hormone assessment, MRI surveillance where indicated and monitoring of visual function.

Examiner's Corner

What are the common causes of hypopituitarism?

Pituitary adenoma.
Craniopharyngioma.
Pituitary surgery or radiotherapy.
Sheehan syndrome.
Pituitary apoplexy.
Head trauma.
Infiltrative disorders (e.g. sarcoidosis or haemochromatosis).
Empty sella syndrome.

How does hypopituitarism present clinically?

Fatigue and reduced exercise tolerance.
Amenorrhoea, infertility or reduced libido.
Loss of secondary sexual characteristics.
Cold intolerance due to secondary hypothyroidism.
Postural hypotension from ACTH deficiency.
Headache and visual field defects if a pituitary mass is present.

Why should glucocorticoids be replaced before thyroxine?

Undiagnosed ACTH deficiency may coexist with secondary hypothyroidism.
Starting levothyroxine first increases cortisol metabolism.
This may precipitate life-threatening adrenal crisis.
Replace glucocorticoids first whenever adrenal insufficiency is suspected.

What investigations confirm hypopituitarism?

Morning cortisol.
Free T4 with TSH.
LH, FSH and sex hormones.
Prolactin.
IGF-1.
MRI of the pituitary gland.
Formal visual field assessment if a pituitary mass is suspected.

Common PACES Viva Questions

What are the common causes of hypopituitarism?
How does ACTH deficiency differ from primary adrenal insufficiency?
Why is there no hyperpigmentation in secondary adrenal insufficiency?
What visual field defect occurs with pituitary adenomas?
What is Sheehan syndrome?
How is pituitary apoplexy managed?
Which hormone should always be replaced first?

Sheehan Syndrome vs Pituitary Apoplexy

Feature	Sheehan Syndrome	Pituitary Apoplexy
Typical trigger	Postpartum haemorrhage	Haemorrhage into a pituitary adenoma
Onset	Usually gradual	Sudden
Headache	Usually absent	Severe
Visual impairment	Uncommon	Common
Key feature	Failure to lactate, amenorrhoea	Acute endocrine emergency

Important Clinical Pearls

Multiple hormone deficiencies suggest pituitary disease rather than isolated endocrine organ failure.
Bitemporal hemianopia strongly suggests compression of the optic chiasm by a pituitary mass.
ACTH deficiency causes hypotension but usually not hyperkalaemia because aldosterone secretion is preserved.
Pituitary MRI is the imaging investigation of choice.
Long-term follow-up is required even after successful treatment.

Pathfinder Pearls

Think pituitary in unexplained fatigue Amenorrhoea is an important clue Check visual fields Replace steroids before thyroxine MRI pituitary is essential Recognise pituitary apoplexy Remember Sheehan syndrome Multiple hormone deficiencies point to hypopituitarism

Common Pitfalls

Attributing chronic fatigue solely to depression without considering endocrine disease.
Failing to assess visual symptoms in patients with suspected pituitary disease.
Starting levothyroxine before excluding or treating ACTH deficiency.
Missing postpartum haemorrhage as a clue to Sheehan syndrome.
Ignoring subtle hypogonadism such as amenorrhoea or reduced libido.
Failing to arrange pituitary imaging when hormone deficiencies are identified.
Not recognising pituitary apoplexy as an endocrine emergency.

Key Take-home Messages

Hypopituitarism should be suspected in patients with unexplained fatigue and multiple endocrine deficiencies.
Always assess for headache and bitemporal visual field loss suggesting a pituitary mass.
Morning pituitary hormone testing and pituitary MRI establish the diagnosis.
Glucocorticoid replacement must precede thyroid hormone replacement if ACTH deficiency is possible.
Early recognition and appropriate hormone replacement can dramatically improve symptoms and quality of life.

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