Endocrine Disorders: Clinical Management and Diagnostics

Posted on May 24, 2026 in Medicine

Thyroid

Graves’ Disease

• Most common cause of thyrotoxicosis
• Autoimmune: IgG antibodies against TSH receptor
• TSH receptor antibodies positive in ~90%
• Exophthalmos + pretibial myxoedema = specific for Graves’
• Smoking = biggest modifiable risk factor for thyroid eye disease
• Clubbing with hyperthyroidism → think Graves’
• Postpartum period may trigger or worsen Graves’
• Radioiodine contraindicated in active eye disease
• Diffuse homogeneous uptake on radioactive iodine scan

Hyperthyroidism

• Hyperthyroidism → oligomenorrhoea/amenorrhoea
• Thyrotoxicosis can cause high-output cardiac failure
• Propranolol used initially for symptom control
• Carbimazole = usual first-line antithyroid drug
• PTU preferred in 1st trimester pregnancy
• Subclinical hyperthyroidism associated with:
  • AF
  • Osteoporosis
  • Dementia

Thyroid Storm

• Treat with:
  • IV beta-blockers
  • Propylthiouracil
  • Hydrocortisone
• Steroids reduce peripheral T4 to T3 conversion

Hypothyroidism and Hashimoto’s

• Hashimoto’s = most common hypothyroidism cause
• Anti-TPO antibodies positive
• Associated with:
  • Other autoimmune disease
  • Thyroid lymphoma / MALT lymphoma
• Hypothyroidism + goitre → Hashimoto’s
• Hypothyroidism → menorrhagia

Levothyroxine

• Iron/calcium reduce absorption → separate by 4 hours
• Pregnancy may require ↑ dose by up to 50%
• Over-replacement → osteoporosis risk
• Raised TSH + normal T4 in treated patient → poor compliance likely

Subclinical Hypothyroidism

• Treat if TSH >10 on 2 occasions
• If TSH 5.5–10:
  • Treat symptomatic patients <65
  • Otherwise observe
• Check TPO antibodies for progression risk
• Elderly patients often “watch and wait”

Thyroiditis

De Quervain (Subacute)

• Painful/tender goitre
• Initial hyperthyroidism → later hypothyroidism
• Reduced iodine uptake globally

Thyroid Cancers

Papillary

• Excellent prognosis
• Early cervical LN spread common
• Monitor thyroglobulin after treatment

Medullary

• Associated with MEN2 + RET oncogene
• Calcitonin used for monitoring

Anaplastic

• Aggressive
• Pressure symptoms common

Thyroid Nodules

• Ultrasound = first-line imaging

Sick Euthyroid Syndrome

• Low T3/T4 + normal TSH in acute illness
• Common in elderly/unwell
• Usually no treatment needed

Myxoedema Coma

• Confusion, hypothermia, bradycardia, hyporeflexia
• Treat with:
  • IV thyroxine
  • IV hydrocortisone

Pituitary

Acromegaly

Diagnosis

• IGF-1 = first-line test
• Confirm with OGTT + serial GH levels

Features

• Bitemporal hemianopia
• Cardiomyopathy

Treatment

• First-line = trans-sphenoidal surgery
• Octreotide if unsuitable for surgery/residual disease

Prolactinoma

Features

• Headache
• Amenorrhoea
• Visual field defects
• Galactorrhoea

Treatment

• Cabergoline/bromocriptine first-line even if neuro symptoms

Prolactin Facts

• Dopamine inhibits prolactin
• Raised prolactin causes (“P’s”):
  • Pregnancy
  • Prolactinoma
  • Physiological
  • PCOS
  • Primary hypothyroidism
  • Phenothiazines
  • Metoclopramide/domperidone

Non-functioning Pituitary Adenoma

• Pressure effects + hypopituitarism
• Mild prolactin rise due to stalk compression
• First-line = trans-sphenoidal surgery
• Pituitary incidentaloma → assess if functional

Adrenal

Addison’s Disease

Features

• Hyponatraemia
• Hyperkalaemia
• Weight loss
• Hypoglycaemia
• Hyperpigmentation (palmar creases)
• No hyperkalaemia/pigmentation in secondary adrenal insufficiency

Causes

• Autoimmune = most common UK cause
• Metastatic malignancy possible

Diagnosis

• Short synacthen test = best test
• 9am cortisol 100–500 = inconclusive

Treatment

• Hydrocortisone + fludrocortisone
• Larger steroid dose earlier in day
• Intercurrent illness → double glucocorticoids only
• Vomiting → IM hydrocortisone
• Give emergency hydrocortisone kit

Addisonian Crisis

Features:

• Hyponatraemia
• Hyperkalaemia
• Hypoglycaemia

Management:

• IV hydrocortisone
• Fluids
• NO fludrocortisone acutely

Cushing’s Syndrome

Features

• Hypokalaemic metabolic alkalosis
• Alcohol excess may mimic

Most Common Endogenous Cause

• Pituitary adenoma (Cushing disease)

Tests

Low-dose Dexamethasone Suppression

• Best initial diagnostic test

High-dose Dexamethasone Suppression

• CT adrenals if high cortisol + low ACTH

Phaeochromocytoma

Features

• Triad:
  • Headaches
  • Sweating
  • Palpitations
• Severe HTN

Investigation

• 24hr urinary metanephrines

Treatment

• Alpha blockade BEFORE beta blockade
• Phenoxybenzamine first
• Definitive = surgery after medical optimisation

Primary Hyperaldosteronism

Features

• HTN + hypokalaemia

Investigation

• Aldosterone:renin ratio first-line
• AVS distinguishes unilateral vs bilateral disease

Causes

• Bilateral adrenal hyperplasia = most common

Treatment

• Spironolactone

Parathyroid / Calcium

Hypercalcaemia

• Most common causes:
  • Malignancy
  • Primary hyperparathyroidism

Investigation

• PTH first test

Malignancy Hypercalcaemia

• Low PTH
• ↑ PTHrP possible

Primary Hyperparathyroidism

Features

• “Bones, stones, groans”
• Depression, constipation, bone pain
• Pepperpot skull
• PTH may be normal
• Most commonly solitary adenoma

Treatment

• Definitive = parathyroidectomy
• Cinacalcet = calcimimetic

Other Facts

• PTH causes phosphate excretion
• Trousseau sign = carpal spasm with BP cuff

Secondary/Tertiary Hyperparathyroidism

• Longstanding secondary → tertiary
• Tertiary = very high PTH + moderately high calcium

Causes Hypercalcaemia

• Thiazides
• Milk-alkali syndrome

Diabetes

Diagnosis

HbA1c ≥48 mmol/mol

• Fasting glucose ≥7.0
• Random glucose ≥11.1
• Asymptomatic patients need repeat confirmation
• HbA1c NOT used for T1DM diagnosis
• Prediabetes = HbA1c 42–47

T1DM

• Low C-peptide
• Autoantibodies useful

Targets

• HbA1c target = 48 mmol/mol
• Check HbA1c every 3–6 months
• Glucose targets:
  • Waking 5–7
  • Pre-meal 4–7

Monitoring

• Test glucose ≥4 times/day

Insulin

• Adults: basal-bolus with detemir
• Children: multiple daily injection basal-bolus

Other

• Keep long-acting insulin during DKA
• Consider metformin if BMI >25
• Every insulin patient should have glucagon kit

T2DM

Core Therapy

• Metformin MR first-line
• Then add SGLT2 inhibitor
• Titrate metformin before starting SGLT2

Add-on Therapy

• DPP4 inhibitor = standard second step
• Add GLP1/tirzepatide if obese/young onset/CVD

If Metformin Contraindicated

• CVD/HF risk → SGLT2 monotherapy
• CKD eGFR <20 → DPP4 inhibitor
• CKD eGFR 20–30 → dapagliflozin/empagliflozin + DPP4

HbA1c Targets

• Standard = 48
• On hypoglycaemia-causing drugs = 53
• Intensify if >58

BP Targets

• <140/90 clinic
• <135/85 home/ABPM

Black Patients + HTN

• ARB first-line

Diabetes Drugs

SGLT2 Inhibitors

• Cause glycosuria
• Benefits:
  • Weight loss
  • CV benefit
• Side effects:
  • UTI
  • Fournier gangrene
  • Euglycaemic DKA
  • Possible amputation risk (canagliflozin)

Sulfonylureas

• Weight gain
• Hypoglycaemia

Pioglitazone

• Fluid retention
• Contraindicated in HF
• Bladder cancer risk

DPP4 Inhibitors

• Increase incretins (GLP1/GIP)

GLP1 Agonists

• Liraglutide useful in obese prediabetics

Orlistat

• Inhibits gastric/pancreatic lipase

DKA / HHS

DKA

Features

• Abdominal pain common
• Can have “unrecordable” glucose

Management

• Initial fluid = isotonic saline
• Fixed-rate insulin 0.1 unit/kg/hr
• Continue long-acting insulin
• Add 10% dextrose once glucose <14
• Cerebral oedema = important complication

Resolution Criteria

• pH >7.3
• Ketones <0.6
• Bicarbonate >15

HHS

• Severe hyperglycaemia (>30 common)
• No major ketosis/acidosis
• Longer history
• Monitor serum osmolality

Serum osmolality = 2(Na+) + glucose + urea

• Insulin only if glucose stops falling with fluids

Hypoglycaemia

Causes/Interpretation

Insulinoma

• Whipple triad
• C-peptide does NOT fall after exogenous insulin

Treatment

• Conscious → oral fast carbohydrate
• Reduced GCS → IV glucose

Driving

• Two assisted hypos → surrender licence
• Insulin users:
  • Check glucose every 2 hrs driving
  • May drive if hypo awareness intact

Water Deprivation Test

Genetics / Syndromes

MEN1

• Peptic ulcers
• Hypercalcaemia
• Galactorrhoea

MEN2A

• Medullary thyroid cancer
• Phaeochromocytoma
• Hypercalcaemia

Kallmann Syndrome

• Anosmia
• Low-normal LH/FSH
• Low testosterone

Klinefelter Syndrome

• Tall
• Infertile
• High LH
• Low testosterone

Turner Syndrome

• Growth hormone may be used

MODY

• Autosomal dominant
• Strong FHx

Steroids

Long-term Steroid Complications

• Osteoporosis
• Proximal myopathy
• Psychosis
• Insomnia
• Neutrophilia
• Avascular necrosis
• Worsened diabetes
• Adrenal suppression

Steroid Withdrawal

Gradual taper if:

• >40 mg pred >1 week
• >3 weeks treatment
• Repeated courses

Sick Day Rules

• Double steroid dose during illness

High-Yield One Liners

• Hypercalcaemia = most common metabolic cancer complication
• Neuroblastoma → ↑ VMA/HVA
• Palpable abdominal mass child → urgent referral
• HbA1c falsely LOW:
  • Haemodialysis
  • Sickle cell
  • Hereditary spherocytosis
• HbA1c falsely HIGH:
  • Splenectomy
• Gastroparesis → bloating + vomiting + erratic glucose
• Diabetic neuropathy = sensory “glove and stocking”
• Monofilament test assesses diabetic neuropathy
• Foot education prevents diabetic gangrene