Endocrinology

Pituitary Gland Disorders in Singapore: Symptoms & Treatment

A pea-sized gland at the base of your brain controls hormone production across your entire body. When the pituitary gland malfunctions, the effects ripple through multiple body systems. The pituitary regulates growth, metabolism, reproduction, stress response, and water balance. A pituitary disorder can manifest as unexplained weight changes, vision problems, or irregular periods.

What is the Pituitary Gland?

The pituitary sits at the base of your brain in a bony cavity called the sella turcica, positioned just behind the bridge of your nose and below the crossing point of the optic nerves (the nerves responsible for vision).

Often called the “master gland,” the pituitary controls other endocrine glands throughout your body by releasing hormones that trigger or regulate hormone production elsewhere. It has two parts:

• Anterior pituitary: Produces growth hormone, thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), prolactin, and reproductive hormones (FSH and LH).
• Posterior pituitary: Stores and releases antidiuretic hormone (ADH), which controls water balance, and oxytocin.

The pituitary operates through feedback loops. When target organs (like the thyroid or adrenal glands) produce sufficient hormones, the pituitary adjusts its signals accordingly. Disruption anywhere in these pathways creates hormone imbalances that specialists can detect through blood tests.

How Pituitary Disorders Develop

Pituitary disorders arise from two main problems:

A growth or lesion in the pituitary (usually an adenoma) can:

• Compress surrounding structures, particularly the optic nerves (causing vision problems)
• Disrupt hormone-producing cells (causing hormone deficiency)
• Produce excess hormones if the growth is hormone-secreting

Damage to the pituitary from surgery, radiation, head trauma, or autoimmune conditions can:

• Reduce hormone production (hormone deficiency)
• Disrupt hormone-releasing signals from the hypothalamus

Most Common Pituitary Disorder – Adenomas

What is a Pituitary Adenoma?

A pituitary adenoma is a benign (non-cancerous) tumour of the pituitary gland. These are classified by:

Size:

• Microadenomas: Less than 10 mm (less likely to cause symptoms)
• Macroadenomas: 10 mm or larger (more likely to compress surrounding structures)

Hormone production:

• Functioning: Produce excess hormones (prolactinomas are most common)
• Non-functioning: Cause no hormone excess but create “mass effect” symptoms by pressing on nearby structures

Pituitary adenomas are the most common pituitary disorder and account for a significant proportion of all tumours in the brain.

Visual Changes – A Key Warning Sign

Why Vision Problems Occur

Large pituitary tumours can compress the optic chiasm—the point where the optic nerves cross just above the pituitary gland. This compression causes characteristic visual changes.

What Patients May Experience

Visual field loss (most common):

• Gradual loss of side (peripheral) vision on both sides (called bitemporal hemianopia)
• Tunnel vision or difficulty seeing in dim light
• Difficulty with depth perception

Eye movement problems:

• Double vision or blurred vision
• Eye movement difficulties

Headaches:

• Frequent headaches, especially behind or above the eyes

Why This Matters

Vision changes often appear before other symptoms, making them an important early warning sign. Formal visual field testing can detect these changes and guide treatment urgency. In many cases, surgical removal of the adenoma results in rapid vision improvement.

Hormone Deficiency – The Most Common Hormonal Problem

Hormone deficiency occurs when the pituitary fails to produce adequate hormones. This is more common than hormone excess and can result from adenomas, surgery, radiation, or autoimmune conditions.

ANTERIOR Hormone Deficiencies (Most Common)

ACTH Deficiency (Adrenal Insufficiency)

Most common anterior deficiency, especially in adults

What patients experience:

• Fatigue and weakness
• Low blood pressure
• Low blood sodium (salt loss)
• Poor stress tolerance
• Weight loss
• During illness or stress: dangerous drops in blood pressure (medical emergency)

Treatment: Hydrocortisone (cortisol replacement) taken daily, with dose increases during illness or stress

TSH Deficiency (Secondary Hypothyroidism)

Second most common anterior deficiency

What patients experience:

• Fatigue and sluggishness
• Weight gain
• Cold intolerance
• Dry skin and thinning hair
• Cognitive slowing
• Low heart rate

Treatment: Levothyroxine (thyroid hormone replacement) taken daily on an empty stomach

Prolactin (PRL) Deficiency

What patients experience:

• Women: Inability to breastfeed after childbirth
• Low libido (in both sexes)
• Reduced sexual function

Treatment: Usually does not require replacement except in specific situations (e.g., desired breastfeeding)

FSH/LH Deficiency (Reproductive Hormone Deficiency)

What patients experience:

• Women: Absent or irregular periods, infertility, reduced libido
• Men: Erectile dysfunction, reduced libido, low energy, infertility
• Both: Decreased bone density over time

Treatment: Sex hormone replacement (varies depending on goals and circumstances)

Growth Hormone (GH) Deficiency

What patients experience:

• Fatigue and reduced exercise tolerance
• Increased body fat (especially around the abdomen)
• Reduced muscle mass
• Decreased bone density
• Reduced quality of life

Treatment: Growth hormone injections when clinically indicated

POSTERIOR Hormone Deficiency (Rare)

ADH Deficiency (Central Diabetes Insipidus)

Much less common than anterior deficiency

What patients experience:

• Excessive urination (polyuria) – passing large volumes of dilute urine
• Extreme thirst (polydipsia)
• Disrupted sleep due to frequent urination
• Risk of severe dehydration if fluid intake is inadequate

Note: This is entirely different from diabetes mellitus (blood sugar disorder)

Treatment: Desmopressin (ADH replacement) administered as nasal spray or tablets

Hormone Excess – Rare But Important

Hormone excess occurs when a functioning adenoma produces excess hormones. This is much less common than hormone deficiency.

Cushing’s Disease (ACTH Excess)

Most common cause of hormone excess from pituitary disorders

What patients experience:

• Weight gain concentrated in the face and trunk
• Thin arms and legs with fat redistribution
• Purple stretch marks
• Easy bruising
• Muscle weakness
• High blood pressure
• Elevated blood sugar
• Mood changes (depression, anxiety)
• Osteoporosis
• Facial puffiness and acne

Treatment:

• Medical management: Medications targeting cortisol production
• Surgical treatment: Transsphenoidal surgery to remove the adenoma (often curative)
• Radiation therapy: If surgery is incomplete

Acromegaly (Growth Hormone Excess)

Second most common cause of hormone excess from pituitary disorders

What patients experience:

• Gradual enlargement of hands and feet (rings and shoes no longer fit)
• Coarsening of facial features (prominent brow, enlarged nose, thickened lips)
• Gradual changes in appearance noticed over years
• Joint pain and stiffness
• Excessive sweating
• Skin thickening and coarsening
• Sleep apnea
• Carpal tunnel syndrome
• Headaches

Treatment:

• Surgical treatment: Transsphenoidal surgery to remove the adenoma
• Medical management: Somatostatin analogues or growth hormone receptor antagonists if surgery incomplete
• Radiation therapy: For residual or recurrent disease

Prolactinoma (Prolactin Excess)

What patients experience:

• Women: Absent or irregular periods, galactorrhoea (milky nipple discharge), infertility, reduced libido
• Men: Erectile dysfunction, breast tissue enlargement (gynecomastia), reduced libido, infertility

Treatment:

• Medical management: Dopamine agonist medications (cabergoline, bromocriptine) – very effective, often curative
• Surgical treatment: Reserved for cases that don’t respond to medication or have mass effect

Other Hormone Excess Conditions (Exceptionally Rare)

FSH/LH excess, TSH excess, and other forms of hormone excess from pituitary adenomas are exceptionally rare.

Medical Emergencies – Pituitary Apoplexy

What is Pituitary Apoplexy?

Sudden bleeding or loss of blood supply within the pituitary gland (most commonly within a pre-existing adenoma) is a medical emergency.

Symptoms Requiring Immediate Medical Attention

• Sudden, severe headache (often the worst headache of your life)
• Vision changes or sudden vision loss
• Eye movement problems or double vision
• Confusion or altered consciousness
• Nausea and vomiting

Why It’s Critical

Without immediate treatment, pituitary apoplexy can cause permanent vision loss, adrenal crisis (life-threatening low cortisol), or coma.

Emergency Treatment

• Immediate high-dose corticosteroids to prevent adrenal crisis
• Urgent MRI to confirm diagnosis
• Surgical decompression if vision is significantly affected or consciousness is declining
• Hospital admission and close monitoring

Diagnosis in Singapore

Initial Evaluation

Your doctor will take a detailed history of your symptoms and perform a physical examination, looking for signs like enlarged hands, facial feature changes, or visual problems.

Visual Field Testing

Formal visual field testing (perimetry) checks for optic nerve compression and provides a baseline for monitoring.

Hormone Blood Tests

Blood tests measure pituitary hormone levels and the hormones of target glands. Timing is critical:

• Cortisol: Must be tested early morning (peaks 7–8 a.m., falls at midnight). Loss of this normal rhythm is a diagnostic marker for Cushing’s disease.
• Growth hormone: Requires stimulation or suppression testing due to fluctuating levels
• Prolactin: May be elevated from stress; mildly elevated results may need confirmation
• Dynamic testing: Stimulating or suppressing hormone production to confirm the pituitary is the source

Imaging Studies

MRI with contrast is the gold standard, detecting adenomas as small as a few millimetres and showing their relationship to surrounding structures.

CT scan is used when MRI is not possible or to detail bony anatomy for surgical planning.

Treatment Approaches

Medical Management

Prolactinomas: Dopamine agonist medications (cabergoline, bromocriptine) are highly effective, shrinking tumours and normalising prolactin in most cases. Surgery is rarely needed.

Acromegaly: Somatostatin analogues (octreotide, lanreotide) or growth hormone receptor antagonists (pegvisomant) when surgery doesn’t achieve remission.

Cushing’s disease: Multiple medication options target different steps in cortisol production. Medical management alone rarely provides long-term control; it’s usually used to prepare patients for surgery or when surgery fails.

Hormone replacement: For hormone deficiency:

• Hydrocortisone for ACTH deficiency
• Levothyroxine for TSH deficiency
• Sex hormones for reproductive hormone deficiency
• Desmopressin for ADH deficiency
• Growth hormone injections when indicated

Your healthcare provider establishes specific treatment goals based on your hormone levels, symptoms, and health profile.

Surgical Treatment

Transsphenoidal surgery is the primary approach for most pituitary adenomas. The surgeon accesses the pituitary through your nasal passages and sphenoid sinus, avoiding brain manipulation and external incisions.

Surgical goals:

• Remove the tumour
• Preserve normal pituitary function
• Decompress the optic nerves (for vision improvement)
• Normalise hormone levels (for functioning adenomas)

Craniotomy (opening the skull) becomes necessary for very large tumours extending significantly beyond the sella turcica.

Radiation Therapy

Radiation is used when surgery doesn’t achieve complete tumour removal or hormone normalisation.

• Stereotactic radiosurgery: High-dose radiation in a single session, suitable for well-defined residual or recurrent tumours at least 2–3 mm from the optic nerves.
• Fractionated radiotherapy: Treatment spread over many sessions, allowing higher total doses while protecting surrounding structures.

Radiation effects on hormone production develop gradually over years. Ongoing hormone monitoring is essential even after successful tumour control.

Living with a Pituitary Condition

Hormone Monitoring

Regular blood tests track hormone levels and guide medication adjustments. Newly diagnosed patients or those with recent treatment need more frequent testing than stable patients.

Imaging Surveillance

MRI monitoring for tumour recurrence or growth: typically annually initially, then less frequently for stable cases.

Medication Management

• Hydrocortisone: Split doses with the largest in the morning to mimic natural cortisol rhythm
• Thyroid medication: Take on an empty stomach, separated from other medications
• Sex hormones & GH: Timing varies; your healthcare provider will provide specific instructions

Sick-Day Dosing

Patients on cortisol replacement must increase their dose during illness or stress to prevent adrenal crisis. Always carry medical identification.

When to Seek Professional Help

• Sudden severe headache with vision changes (possible pituitary apoplexy—emergency)
• New or worsening vision loss or visual field changes
• Unexplained milky nipple discharge
• Gradual changes in facial appearance or hand/foot size
• Unexplained fatigue with low blood pressure
• Excessive thirst with frequent, dilute urination
• Women: Absent periods not explained by pregnancy or menopause
• Men: Erectile dysfunction with reduced libido and energy
• Persistent symptoms despite hormone replacement

Frequently Asked Questions

Will I need lifelong medication after pituitary surgery?

This depends on the tumour type and amount of normal pituitary tissue remaining. Some patients require no replacement. Others need one or two hormones replaced. Some need comprehensive hormone replacement. Your healthcare provider will monitor hormone levels and establish a plan based on your recovery.

How quickly do pituitary tumours grow?

Growth rates vary significantly. Many microadenomas remain stable for years. Others grow measurably within months. Regular imaging surveillance identifies growth patterns and guides treatment timing.

Is pituitary disorder hereditary?

Most pituitary tumours occur sporadically without inherited causes. However, some genetic syndromes include pituitary tumours: MEN1, MEN4, Carney complex, familial isolated pituitary adenoma (FIPA), and X-linked acrogigantism. Your healthcare provider may recommend genetic counselling if you developed a pituitary tumour at a young age, have a family history of endocrine tumours, or have a tumour subtype associated with heritable syndromes.

Can lifestyle changes help manage my condition?

Lifestyle modifications cannot cure pituitary gland disorders. However, maintaining a healthy weight, regular exercise, adequate sleep, and stress management support overall well-being and may improve how you feel alongside medical treatment. Certain conditions have specific dietary considerations; your healthcare provider can discuss these based on your needs.

NEXT STEPS

Pituitary disorders are managed through:

• Hormone testing to identify specific deficiencies or excesses
• MRI imaging to assess tumour size and location
• Coordinated care involving endocrinologists, neurosurgeons, and ophthalmologists (depending on structures affected)
• Medication management, surgery, or radiation based on your specific diagnosis

If you are experiencing vision loss, unexplained milky nipple discharge, gradual enlargement of your hands or facial features, or symptoms of hormone excess or deficiency, consult an endocrinologist for a comprehensive pituitary evaluation.