Differential Diagnosis

Question 1

Acute Shortness of Breath

Answer 1

Common - asthma, exacerbation of COPD, pneumonia, left ventricular failure or hyperventilation.

Less common - pneumothorax, pulmonary embolism, pleural effusion, diabetic ketoacidosis or lobar collapse.

Rare - aspiration pneumonitis, Guillain-Barre syndrome, hypovolaemic shock, adult respiratory distress syndrome or laryngeal obstruction.

Question 2

Chest Pain

Answer 2

Common - acute coronary syndrome, GORD, musculoskeletal pain, Da costa’s syndrome or Tietze’s syndrome.

Less common - pleurisy (infection), peptic ulcer, biliary colic, mastitis, shingles or Bornholm disease.

Rare - pulmonary embolism, pericarditis or myocarditis, fractured rib, pneumothorax, hypertrophic obstructive cardiomyopathy or dissecting aortic aneurysm.

Question 3

Chronic Shortness of Breath

Answer 3

Common - asthma, COPD, congestive heart failure, anaemia or obesity.

Less common - pleural effusion, bronchial carcinoma with lobar collapse, bronchiectasis, recurrent pulmonary embolism, aortic stenosis or chronic hyperventilation.

Rare - fibrosing alveolitis, extrinsic allergic alveolitis (bird-fancier’s lung), large hiatus hernia, sarcoidosis, neurological condition (motor neurone disease or muscular dystrophy).

Question 4

Cough

Answer 4

Common - URTI, LRTI, ashtma, GORD or chronic sinusitis / rhinitis.

Less common - COPD, bronchial carcinoma, left ventricular failure, ACEi side effect, bronchiectasis or psychogenic.

Rare - inhaled foreign body, interstitial lung disease (alveolitis, radiotherapy or sarcoidosis), tuberculosis, cystic fibrosis, laryngeal carcinoma or a foreign body in the ear canal.

Question 5

Haemoptysis

Answer 5

Common - respiratory tract infection, pulmonary embolism, bronchogenic carcinoma, pulmonary oedema or due to prolonged coughing.

Less common - bronchiectasis, laryngeal or tracheal carcinoma, tuberculosis, mitral stenosis or polyarteritis nodosa.

Rare - contusion due to trauma, SLE, Goodpasture’s syndrome, aspergillosis or hereditary haemorrhagic telangiectasia.

Question 6

Palptations

Answer 6

Common - sinus tachycardia (stress, fever, exercise), atrial or ventricular ectopics, supraventricular ectopics or anxiety.

Less common - thyrotoxicosis, atrial fibrillation, atrial flutter, menopause or iatrogenic (e.g. digoxin or nifedipine)

Rare - heart block, sick sinus syndrome, drug abuse or ventricular tachycardia.

Question 7

Abdominal Swelling

Answer 7

Common - pregnancy, IBS, constipation, fibroids or an enlarged bladder.

Occasional - ascites, intestinal obstruction, ovarian mass, carcinoma or the stomach or colon or hepatomegaly.

Rare - splenomegaly, pancreatic carcinoma, aortic aneurysm, para-aortic lymphadenopathy, hydronephrosis, renal cysts or renal malignancy.

Question 8

Acute abdominal pain in adults

Answer 8

Common - peptic ulcer, biliary colic, appendicitis, gastroenteritis or renal colic.

Occasional - cholecystitis, diverticulitis, bowel obstruction, pyelonephritis, muscular wall pain or pancreatitis.

Rare - bowel perforation, hepatitis, IBD, ischaemic bowel, dissecting aortic aneurysm or DKA.

Question 9

Chronic abdominal pain in adults

Answer 9

Common - IBS, constipation, recurrent UTI, chronic peptic ulcer or diverticular disease.

Less common - inflammatory bowel disease, coeliac disease, gallstones, ureteric colic or hydronephrosis.

Rare - chronic pancreatitis, subacute bowel obstruction, mesenteric artery ischaemia, malignancy or functional (psychogenic) abdominal pain.

Question 10

Acute abdominal pain in pregnancy

Answer 10

Common - symphysis pubis and ligament strain, miscarriage, premature labour, placental abruption or pyelonephritis.

Occassional - constipation, ectopic pregnancy, appendicitis, red degeneration of a fibroid or torsion or rupture of a ovarian cyst.

Rare - uterine rupture, uterine torsion, liver congestion due to pre-eclampsia or rectus sheath haematoma.

Question 11

Epigastric pain

Answer 11

Common - GORD, duodenal ulcer, non-ulcer dyspepsia, gallstones or IBS.

Less common - gastric ulcer, oesophageal spasm, carcinoma of the stomach, pancreatitis, muscular pain or drug related pain (NSAIDs, antibiotics or bisphosphonates).

Rare - myocardial infarct, pneumonia, ruptured abdominal aortic aneurysm, epigstric hernia, carcinoma of the pancreas or referred pain from the spine.

Question 12

Diarrhoea

Answer 12

Common - acute gastroenteritis, IBS, drug side effect (antibiotics), diverticulitis or overflow constipation.

Less common - IBD, chronic gastroenteritis, lactose intolerance, bowel neoplasia, excess alcohol, toddler diarrhoea or coeliac disease.

Rare - thyrotoxicoxix, laxative misuse, appendicitis or allergy.

Question 13

Constipation

Answer 13

Common - diet (inadequate fibre), lifestyle (ignoring the urge to defecate), inactivity, IBS, painful perianal conditions (fissure, haemorrhoids, abscess or warts) or drugs (opiates, iron or aluminium hydroxide).

Less common - poor fluid intake, hypothyroidism, carcinoma of the rectum or colon or acquired megacolon (chronic laxative abuse, neurological problems or scleroderma).

Rare -

Question 14

Vomiting

Answer 14

Common - gastroenteritis, upper respiratory tract infection, appendicitis (acute abdomen), pregnancy or acute labyrinthitis.

Less common - migraine, medication side effect (antibiotics or cytotoxics), pyelonephritis, ureteric calculus, intestinal obstruction, hyper or hypoglycaemia.

Rare - meningitis, raised intracranial pressure, cerebral haemorrhage, actue glaucoma, bulimia nervosa, severe constipation or renal failure.

Question 15

Haematemesis

Answer 15

Common - peptic ulcer, acute gastritis, GORD, Mallory-Weiss tear, oesophageal varices (alcoholic cirrhosis) or malignancy (stomach or oesophageal).

Less common - swallowed blood (nose bleed or haemoptysis), ingested poisons (corrosive acid or alkali) or oesophageal perforation (by foreign body or mediastinal tumour),

Rare - ruptured oesophagus (acute vomiting or trauma) or Munchausen’s syndrome (swallowing blood).

Question 16

Rectal Bleeding

Answer 16

Common - haemorrhoids, anal fissure, diverticular disease, rectal carcinoma or gastroenteritis.

Less common - Inflammatory bowel disease, colonic carcinoma, villous adenoma, trauma (NAI in children) or anticoagulation therapy.

Rare - bowel ischaemia, intussusception, blood clottting disorders, angiodysplasia or Meckel’s diverticulum (only in children).

Question 17

Haematuria

Answer 17

Common - urinary tract infection, renal or ureteric caliculi, bladder carcinoma, urethritis, prostatic hypertrophy or prostatic carcinoma.

Less common - vigorous exercise, chronic interstitial cystitis, glomerulonephritis, renal cell carcinoma or anticoagulant therapy.

Rare - polycystic kidney disease, schistosomiasis, infective endocarditis, renal tuberculosis or trauma.

Question 18

Excessive urination

Answer 18

• Common causes - diabetes mellitus, diuretic therapy, chronic renal failure, hypercalcaemia (osteoporosis treatment, bony mets or hyperparathyroidism) or alcohol.
• Less common causes - cranial diabetes insipidus, potassium depletion (chronic diarrhoea, diuretics, hyperaldosteronism), relief of chronic urinary obstruction, drugs (lithium, amphotericin B or gentamicin), Cushing’s disease (from excess corticosteroids or ACTH secreting tumour) or early chronic pyelonephritis.
• Rare causes - psychogenic polydipsia, nephrogenic diabetes insipidus (X linked so males only), Fanconi syndrome or DIDMOAD syndrome (diabetes insipidus and mellitus, optic atrophy and deafness).

Question 19

Urinary frequency

Answer 19

• Common causes - infective cystitis, bladder caliculi, detrusor instability, prostatism (hypertrophy or carcinoma) or anxiety.
• Less common causes - interstitial cystitis (non-infective), prostatitis, urethritis or pyelonephritis, pregnancy, iatrogenic (e.g. diuretics) or bladder neck hypertrophy.
• Rare causes - pelvic space occupying lesion (e.g. fibroid, ovarian cyst or carcinoma), secondary to pelvic inflammation (e.g. PID, appendicitis or diverticulitis), bladder tumour (benign or malignant), post-radiotherpy fibrosis or fibrosis secondary to chronic sepsis from long term catheterisation.

Question 20

Incontinence

Answer 20

• Common causes - stress incontinence (with or without prolapse), infective cystitis, detrusor instability (idiopathic or 2° to CVA or dementia), chronic outflow obstruction or post-prostatectomy (usually temporary).
• Less common causes - chronic urinary tract infection, interstitial cystitis, bladder caliculi or tumour, after abdomino-pelvic surgery and radiotherapy, fistula (e.g. vesicovaginal/uterine or ureterovaginal) or polyuria (in diabetes or with diuretics).
• Rare causes - post-pelvic fracture (direct sphincter or neurological damage), congenital abnormalities, sensory neuropathy (e.g. diabetes or syphilis), paraplegia or cauda equine syndrome or psychogenic.

Question 21

Nocturia

Answer 21

• Common causes - age related (reduction in bladder capacity), excess fluid at bedtime (especially alcohol), any cause of ankle oedema (due to redistribution), cystitis or prostatism.
• Less common causes - lower urinary tract obstruction, diabetes mellitus, any cause of polyuria or urinary frequency or unstable bladder.
• Rare causes - anxiety, drug side effect or diabetes insipidus.

Question 22

Urinary retention

Answer 22

• Common causes - prostatic hypertrophy (usually benign), bladder neck or urethral obstruction, UTI (including prostatitis and a prostatic abscess, constipation or anticholinergic drugs (bladder stabilisers and tricyclic antidepressants).
• Less common causes - a pelvic mass (e.g. retroverted, gravid or fibroid uterus), urethral calculus, holding on (leads to prostatic congestion) or clot retention (e.g. after bleeding from a tumour or post-TURP bleed).
• Rare causes - neurological (e.g. MS, syphilis or spinal cord compression), traumatic rupture of the urethra, foreign body inserted into the urethra, phimosis or psychological.