Diabetes, Thyroid, Kidney and Urology: The PLAB 1 Domain Explained

Scope and time budget

Fourteen questions is about fourteen minutes. This domain contains both fast emergency items and slower interpretation items, such as a set of renal results, a glucose chart or a thyroid profile. Allow slightly longer for result-heavy stems and recover the time on short recall items.

What is tested

• Diabetes. Type 1 diabetes and diabetic ketoacidosis, type 2 diabetes and the NICE drug pathway with HbA1c targets, hyperosmolar hyperglycaemic state and hypoglycaemia, and complications: retinopathy, nephropathy, neuropathy and foot disease.
• Thyroid, adrenal and pituitary. Thyrotoxicosis, thyroid storm and hypothyroidism, Cushing's, Addison's and phaeochromocytoma, hyperprolactinaemia and acromegaly.
• Bone and metabolism. Calcium disorders and parathyroid disease, osteoporosis, obesity, metabolic syndrome and bariatric surgery.
• Kidney. Acute kidney injury with causes, KDIGO staging and management, chronic kidney disease staging and drug dosing, nephrotic and nephritic syndromes, renal replacement therapy and transplantation.
• Urology. Urinary tract infection and pyelonephritis, stones and renal colic, benign prostatic hyperplasia and prostate cancer with PSA, testicular torsion and epididymo-orchitis, bladder and kidney cancer with the haematuria pathway, retention, incontinence and catheter care.

UK points to anchor your answers

• DVLA and insulin: insulin-treated diabetes must be notified. For Group 1, licences are issued for 1, 2 or 3 years, and drivers test glucose at the start of the first drive and at least every 2 hours while driving. For Group 2, licences are for 1 year with annual specialist review, a meter that stores 4 weeks of readings, testing at least twice daily and every 2 hours when driving.
• Severe hypoglycaemia: an episode requiring the assistance of another person. Group 1 must stop and notify after two or more awake severe episodes in 12 months. Group 2 must stop and notify after any severe episode in 12 months, including while sleeping.
• Continuous glucose monitoring: a driver who relies on alarms to recognise hypoglycaemia must stop and notify, and a finger-prick meter must still be carried.
• Eye screening: everyone with diabetes from age 12, at regular intervals.
• Units and names: HbA1c in mmol/mol, glucose and electrolytes in mmol/L, creatinine in micromol/L, and UK drug names.

NICE sets the type 2 diabetes drug pathway and HbA1c targets, and the BNF sets doses. We could not read those sites for this page, so we give no numeric targets. Confirm them at source.

What examiners ask about each group

• DKA and hyperglycaemic states. Recognise the picture, start fluids and insulin in the right order, monitor potassium, and know the sick-day rules for a patient on insulin.
• Type 2 diabetes. Choose the next drug for a patient with cardiovascular disease, heart failure or kidney disease, and spot adverse effects and contraindications.
• Thyroid and adrenal. Interpret the thyroid profile, recognise a crisis and give the correct first treatment. For adrenal insufficiency, know why steroids must not be stopped abruptly and how to cover illness and surgery.
• AKI. Look for the cause, stop nephrotoxic and renally cleared drugs, assess fluid status and know when obstruction needs urgent imaging and referral.
• CKD. Understand staging, complications and drug dose adjustment.
• Urology. Separate torsion from epididymitis, recognise retention and know the red flags for urological cancer.

How the questions are framed

Endocrine and renal stems are often result-driven. You may be given a blood glucose and ketone result, a set of electrolytes with creatinine, a thyroid profile, a calcium with parathyroid hormone or a urine dipstick. The question asks what the result means and what to do next. The best preparation is to practise reading a result before you read the options, then testing your reading against the choices.

Drug items are frequent. They ask which agent to add, which to stop and which to avoid, usually because of a kidney, heart or liver problem hidden in the stem. Know the common adverse effects and contraindications of metformin, sulfonylureas, SGLT2 inhibitors, insulin, levothyroxine, steroids, diuretics, ACE inhibitors and anti-inflammatory drugs, and how kidney function changes their use.

Questions on long-term disease usually reward screening and prevention: eye and foot checks, kidney monitoring, bone protection on steroids and cardiovascular risk reduction. These are easy marks when you read the stem for the person's age, duration of disease and existing complications.

Time management in this domain

Result-heavy stems are the main time risk. Train yourself to scan the numbers once, note which are abnormal, and move straight to the pattern. If a stem has six results and you can only explain three, re-read the question and ask what decision the examiner wants. It is rarely a full interpretation of every number.

Three typical traps

1. Stopping the wrong drug in AKI. The stem may list an ACE inhibitor, a diuretic, an anti-inflammatory drug and metformin. Decide which ones to hold and why, using the BNF and NICE.
2. Giving insulin before checking potassium in DKA. The exam tests the safe order: fluids, then insulin with potassium monitoring and replacement as the result requires. Check the stem for a potassium value.
3. Forgetting the testicular emergency. A young man with sudden scrotal pain needs urgent surgical exploration before any scan delays it. Do not choose antibiotics and reassessment.

How to revise it

1. Write an emergency card for DKA, HHS, hypoglycaemia, thyroid storm, adrenal crisis and AKI. Include the first action, fluids, drugs and monitoring.
2. Learn the type 2 pathway as a flowchart from the NICE source, with the branch for cardiovascular and renal disease.
3. Practise reading results. Ten minutes a day on renal function, electrolytes, thyroid profiles and calcium.
4. Memorise the DVLA diabetes rules by contrasting Group 1 and Group 2.
5. Do 20-question timed blocks and log errors by cause.

This domain links to cardiovascular for risk reduction, to child health for type 1 diabetes in children, and to the professional and therapeutics domain for renal dose adjustment.