Differentials

Common

Essential hypertension

History

often asymptomatic; headaches, visual disturbance, nosebleeds, or neurological symptoms possible

Exam

may have signs of end organ damage; heave due to left ventricular hypertrophy, retinopathy, functional deficit following stroke; lack of signs to suggest a secondary cause

1st investigation
  • ECG:

    normal, evidence of previous MI or left axis deviation with left ventricular hypertrophy

  • urea/creatinine:

    normal, or elevated with renal impairment

  • serum cholesterol:

    variable

  • random blood glucose:

    >8 mmol/L on non-fasting sample suggestive of comorbid diabetes and fasting blood sugar advised

  • urinalysis:

    may be normal

    More
Other investigations

    Renal artery stenosis

    History

    often asymptomatic; headaches, visual disturbance, nosebleeds, or neurological symptoms possible; difficult-to-treat hypertension; peripheral vascular disease; may present with flash pulmonary oedema

    Exam

    bruit over the abdomen

    1st investigation
    • plasma renin activity:

      elevated

    Other investigations
    • renal angiogram:

      narrowing of renal artery

    • renal MRI:

      narrowing of renal artery

    Chronic kidney disease

    History

    known renal impairment; usually asymptomatic; may present with headaches, visual disturbances, neurological deficits (e.g., transient ischaemic attack or stroke), or nose bleeds, fatigue, nausea, anorexia; difficult-to-treat hypertension suggests possible renal cause[67]

    Exam

    features of chronic renal failure: oedema, arteriovenous fistulae, pale conjunctiva secondary to anaemia

    1st investigation
    • urinalysis:

      albuminuria, casts in the urine

    • urea/creatinine:

      elevated creatinine and urea

    • renal ultrasound:

      small kidneys

    Other investigations

      Obstructive uropathy

      History

      variable depending on cause; may report previous urethral instrumentation, flank pain with nephrolithiasis, hesitancy, frequency, and poor stream with prostatic enlargement

      Exam

      variable; enlarged prostate on rectal examination, flank tenderness with renal calculi

      1st investigation
      • renal ultrasound:

        may show hydronephrosis or small kidneys with resultant chronic renal failure

      • urea/creatinine:

        elevated creatinine

      Other investigations
      • non-contrast CT pyelogram:

        demonstrates renal calculi if present

      Obstructive sleep apnoea/hypopnoea syndrome

      History

      sleeping for long periods of time, loud snoring, excessive daytime sleepiness, restless sleep, erectile dysfunction, morning headaches, GORD, and weight gain. Total score of ≥11 on Epworth sleepiness scale supports the diagnosis.

      Exam

      maxillomandibular abnormalities, macroglossia

      1st investigation
      • polysomnography:

        apnoea/hypopnoea index (AHI) ≥15 episodes/hour or AHI ≥5 events/hour with symptoms

        More
      • portable multichannel sleep tests:

        Respiratory Event Index (REI) of ≥15 episodes/hour or REI ≥5 with symptoms

        More
      Other investigations
      • fibre-optic endoscopy:

        may see nasal polyps or tumours, or hypertrophic lingual tonsils

      Obesity hypoventilation syndrome

      History

      obesity (BMI ≥30 kg/m²), dyspnoea, nocturia, lower extremity oedema, excessive daytime sleepiness, fatigue, loud disruptive snoring, witnessed apnoeas, waking headaches, unexplained polycythaemia

      Exam

      mild hypoxemia awake, with significant hypoxaemia when asleep, awake daytime hypercapnia

      1st investigation
      • serum bicarbonate screen:

        >24 mmol/L (>24 mEq/L)

        More
      • Arterial blood gas:

        PaCO₂ >45 mmHg

        More
      Other investigations
      • polysomnography:

        demonstrates hypoventilation, particularly during REM sleep

        More

      Uncommon

      Coarctation of aorta

      History

      often asymptomatic; headaches, visual disturbance, nosebleeds, or neurological symptoms possible; cold legs, sweating

      Exam

      disparity in the blood pressure readings between both arms (left arm typically 20 mmHg lower than the right arm), radio-femoral delay, systolic or continuous murmurs over lateral chest wall, absence of pedal pulses

      1st investigation
      • ECG:

        left ventricular hypertrophy

      • echocardiogram:

        left ventricular hypertrophy ± bicuspid aortic valve

        More
      • chest x-ray:

        widening of left subclavian border, double bulge above and below the usual site of the aortic knuckle, rib notching due to collaterals

      Other investigations
      • MRI scan of aorta:

        coarctation is clearly defined and used to plan further management

      Pre-eclampsia

      History

      pregnant woman, >20 weeks' gestation, usually >32 weeks' gestation, can be asymptomatic, may have facial or limb swelling, may have epigastric pain that radiates to the back

      Exam

      newly elevated blood pressure >140/90 mmHg on 2 readings 6 hours apart, may have facial or limb pitting oedema

      1st investigation
      • urinalysis/24-hour urine collection:

        positive reagent strip test; urinary excretion of ≥300 mg of protein in 24 hours; or urine protein:creatinine ratio ≥30 mg/mmol; albumin:creatinine ratio of ≥8 mg/mmol; may be normal

        More
      • placental growth factor:

        low

        More
      Other investigations
      • fetal ultrasound:

        variable depending on severity; fetal biometry may reveal fetal growth restriction

      • coagulation screen:

        typically normal

        More

      Glomerulonephritis

      History

      nausea, malaise, weight loss, fever, features of underlying aetiology (e.g., arthralgia)

      Exam

      oedema with nephrotic features, hypervolaemia, signs of underlying aetiology; skin rash

      1st investigation
      • urinalysis:

        dysmorphic red blood cells, sub-nephrotic proteinuria, and active sediment

      • 24-hour urine collection:

        proteinuria is generally <3.5 g/day

      Other investigations
      • renal biopsy:

        characteristic findings on light and immunofluorescence microscopy

      Nephrotic syndrome

      History

      swelling of the legs, hands, face; foamy urine

      Exam

      hypoalbuminaemia, xanthelasma, oedema

      1st investigation
      • spot urinary albumin to creatinine ratio:

        >3.5

        More
      • urinary microscopy:

        cellular casts

      Other investigations
      • renal biopsy:

        variable

        More

      Polycystic kidney disease

      History

      haematuria, headaches, abdominal pain, elevated blood pressure often presenting feature in young patients (20 to 34 years); family history of polycystic kidneys, or intracranial aneurysm, or subarachnoid haemorrhage

      Exam

      palpable kidneys; hepatomegaly, inguinal, incisional, and para-umbilical hernias are not uncommon

      1st investigation
      • renal ultrasound:

        30 years of age: at least 2 unilateral or bilateral cysts; 30-59 years of age: 2 cysts in each kidney; >60 years of age: 4 cysts in each kidney

      • urinalysis:

        proteinuria, increased urinary albumin excretion, and haematuria are common

        More
      Other investigations

        Phaeochromocytoma

        History

        usually asymptomatic; may present with headaches, visual disturbances, neurological deficits (e.g., transient ischaemic attack or stroke), or nose bleeds; symptoms of the hyper-adrenergic state: palpitations, panic attacks, cold clammy skin, pallor, abdominal cramps[79]

        Exam

        no specific findings, features of hypertension-mediated organ damage possible

        1st investigation
        • urinary catecholamines, vanillylmandelic acid, and metanephrins:

          levels twice the laboratory reference range are suggestive

        • plasma metanephrins:

          levels twice the laboratory reference range are suggestive

          More
        Other investigations
        • CT or MRI of adrenals:

          localisation of lesion if presence suggested by initial tests

        Hyperaldosteronism

        History

        usually asymptomatic (patients are typically normokalaemic); if serum potassium is low: headaches, tiredness, nocturia, paraesthesiae, muscle cramps, palpitations

        Exam

        no specific findings, features of hypertension-mediated organ damage possible

        1st investigation
        • plasma potassium:

          normal; low, <3.0 mmol/L in 20% of patients

          More
        • plasma renin activity:

          decreased

          More
        Other investigations
        • CT or MRI of adrenals:

          localisation of adenoma/tumour

        • adrenal vein sampling:

          aldosterone to cortisol ratio >2 between sides suggestive of aldosterone-secreting tumour

        Cushing's disease/syndrome

        History

        psychiatric symptoms, weight gain, hirsutism, easy bruisability, decreased libido

        Exam

        supraclavicular fullness due to fat deposition, facial plethora, violaceous striae

        1st investigation
        • late-night salivary cortisol:

          elevated

        • 1 mg overnight dexamethasone suppression test:

          >50 nanomol/L (1.8 microgram/dL)

          More
        • 24-hour urinary free cortisol:

          >50 micrograms/24 hours

        Other investigations

          Hyperthyroidism

          History

          heat intolerance, sweating, weight loss, palpitations, tremor

          Exam

          tachycardia, proptosis, exophthalmos, cardiac flow murmur

          1st investigation
          • thyroid-stimulating hormone:

            suppressed

            More
          • serum free T4:

            elevated above normal range

          • serum free or total T3:

            elevated above normal range

          Other investigations

            Hypothyroidism

            History

            weight gain, lethargy, depression, constipation

            Exam

            dry skin, bradycardia, thick tongue, eyelid oedema

            1st investigation
            • serum thyroid-stimulating hormone:

              elevated above normal range

            • free serum T4:

              below normal range

            Other investigations

              Hyperparathyroidism

              History

              fatigue, anxiety, depression, bone pain, paraesthesiae, myalgia

              Exam

              band keratopathy (deposition of calcium just inside the iris on eye examination), fibro-osseous jaw tumours on palpation (uncommon)

              1st investigation
              • serum calcium:

                elevated

                More
              • serum PTH levels:

                normal or elevated

              Other investigations

                Chronic alcohol excess

                History

                central nervous system excitability on withdrawal of alcohol, dependency behaviour, tolerance; social, economic, or legal problems

                Exam

                jaundice, hepatomegaly, evidence of cirrhosis; spider nevi, ascites

                1st investigation
                • diagnostic interview:

                  Structured Clinical Interview for DSM (SCID) can be administered by non-clinicians and can replace a psychiatric interview; at least 2 of the 11 DSM-5 criteria for alcohol-use disorder must be present

                • gamma glutamyl transferase, alanine aminotransferase, and aspartate aminotransferase:

                  elevated

                Other investigations

                  Medication

                  History

                  chronic use of non-steroidal anti-inflammatory drugs or current use of oral contraceptives, glucocorticoids, ciclosporin, atypical antipsychotics, or vascular endothelial growth factor receptor tyrosine kinase inhibitors

                  Exam

                  no specific examination findings

                  1st investigation
                  • trial discontinuation of medication:

                    elevated blood pressure resolves

                    More
                  Other investigations

                    Illicit drug use

                    History

                    history of use of vasoactive illicit drug (e.g., cocaine, metamfetamine) and/or non-compliance with prescribed medications; nervousness, restlessness, tremors, anxiety, irritability; hostility and exaggerated strength; headache; abdominal pains; hallucinations, convulsions, delirium, unconsciousness, seizures

                    Exam

                    constricted or dilated pupils, cold extremities, tachycardia; nervousness, restlessness, tremors, anxiety, and irritability; rise in body temperature/hyperthermia; enhanced reflexes; irregular respiration

                    1st investigation
                    • urinary toxicology:

                      positive for illicit drug (e.g., cocaine or metamfetamine)

                      More
                    • serum toxicology:

                      positive for illicit drug (e.g., cocaine or metamfetamine)

                      More
                    Other investigations

                      'White-coat hypertension'

                      History

                      asymptomatic, elevated blood pressure readings in clinic but normal readings at home or outside hospital environment

                      Exam

                      no evidence of end organ damage as hypertension is not sustained outside clinical environment

                      1st investigation
                      • 24-hour blood pressure monitoring:

                        normal

                        More
                      Other investigations

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