Thyroid disorders: too fast or too slow
Thyroid hormone sets metabolic rate, so hyperthyroidism accelerates almost every system. Expect weight loss despite increased appetite, heat intolerance, tachycardia, palpitations, atrial fibrillation, tremor, anxiety, insomnia, diarrhoea and, in Graves' disease, exophthalmos. Nursing care emphasises a cool quiet environment, a high-calorie high-protein diet, rest and eye protection where exophthalmos is present.
Thyroid storm is the emergency form, usually precipitated by infection, surgery or abrupt medication discontinuation. It presents with extreme fever, severe tachycardia, hypertension, agitation and delirium progressing to coma. The response is immediate: notify the provider, cool the client, monitor cardiac rhythm and prepare for beta blockade and antithyroid therapy.
Hypothyroidism produces the mirror image: weight gain, cold intolerance, bradycardia, constipation, dry skin, coarse hair, fatigue, depression and slowed cognition. Levothyroxine is taken on an empty stomach in the morning, at least thirty minutes to an hour before food, and lifelong. Myxoedema coma is the emergency form with hypothermia, hypotension, hypoventilation and altered consciousness.
| Feature | Hyperthyroidism | Hypothyroidism |
|---|---|---|
| Weight | Loss despite good appetite | Gain despite poor appetite |
| Temperature tolerance | Heat intolerance | Cold intolerance |
| Heart rate | Tachycardia, atrial fibrillation | Bradycardia |
| Bowel | Diarrhoea | Constipation |
| Mood and cognition | Anxiety, restlessness, insomnia | Depression, fatigue, slowed thinking |
| Emergency form | Thyroid storm | Myxoedema coma |
Adrenal disorders: Addison's versus Cushing's
Addison's disease is adrenal insufficiency — too little cortisol and aldosterone. Without aldosterone the client loses sodium and water and retains potassium, so expect hypotension, hyponatraemia, hyperkalaemia, hypoglycaemia, weight loss, fatigue, salt craving and bronze hyperpigmentation. Adrenal crisis presents with profound hypotension, severe weakness, vomiting and shock, and is treated with intravenous hydrocortisone and fluids urgently.
Cushing's syndrome is cortisol excess, most commonly from exogenous corticosteroid therapy. Expect central obesity with thin extremities, a moon face and buffalo hump, fragile skin with purple striae, easy bruising, hyperglycaemia, hypertension, hypokalaemia, osteoporosis and immunosuppression that masks infection.
The teaching that matters most on the exam is that clients on long-term corticosteroids must never stop them abruptly, because the adrenal glands have suppressed their own production and abrupt withdrawal can precipitate adrenal crisis. Doses are increased during physiological stress such as illness, injury and surgery, and clients should carry medical identification.
- •Addison's: low sodium, high potassium, low glucose, low blood pressure
- •Cushing's: high sodium, low potassium, high glucose, high blood pressure
- •Adrenal crisis: hypotension and shock — hydrocortisone and fluids now
- •Never stop long-term steroids abruptly; increase during illness
SIADH and diabetes insipidus
Antidiuretic hormone controls water retention, so the two disorders of this hormone are exact opposites and are frequently paired in exam questions. In syndrome of inappropriate antidiuretic hormone, too much hormone causes water retention, producing dilutional hyponatraemia, concentrated urine, weight gain without oedema, and neurological symptoms ranging from headache and confusion to seizures.
Management of SIADH centres on fluid restriction, daily weights, strict intake and output, seizure precautions and cautious sodium correction. Correcting sodium too quickly is dangerous, which is why an item offering rapid hypertonic saline without qualification is often a distractor.
In diabetes insipidus, too little antidiuretic hormone causes massive water loss: several litres of very dilute urine daily, intense thirst, dehydration, hypernatraemia and rising serum osmolality. Management includes desmopressin, generous fluid replacement, daily weights and close monitoring of neurological status and urine specific gravity.
| Parameter | SIADH | Diabetes insipidus |
|---|---|---|
| ADH level | Excessive | Deficient |
| Urine output | Low and concentrated | Very high and dilute |
| Serum sodium | Low | High |
| Urine specific gravity | High (> 1.030) | Low (< 1.005) |
| Weight | Gain | Loss |
| Core treatment | Fluid restriction | Desmopressin and fluid replacement |
Answering endocrine items efficiently
Start by naming the hormone and deciding whether the stem describes excess or deficiency. Then predict the expected laboratory pattern before reading the options. If the option set contradicts your prediction, re-read the stem rather than abandoning the physiology; more often than not the stem contains a detail you skipped.
Watch for the safety layer that sits on top of the physiology. Clients with severe hypothyroidism are sensitive to sedatives and opioids. Clients with hyperthyroidism are at risk of cardiac dysrhythmias. Clients on corticosteroids have muted infection signs. These safety overlays are where the priority answer usually lives.
Finally, remember that teaching options often outrank monitoring options in stable clients, because an endocrine client's long-term outcome depends heavily on medication adherence and self-management. Choosing to teach medication timing, sick-day rules and warning signs is frequently the intended answer when no acute instability exists.