​Differential diagnosis of rheumatological causes of carpal tunnel syndrome are : 
-dermatomyositis 
-systemic lupus erythematosus 
-scleroderma 
-rheumatoid arthritis 
-degenerative arthritis 

​Differential diagnosis of metabolic, endocrine causes of carpal tunnel syndrome are : 
-uremia 
-paraproteinemia 
-Paget’s disease
-mucopolysaccharidoses
-hypothyroidism 
-gout 
-estrogens 
-diabetes mellitus 
-amyloidosis 
-acromegaly 

​Differential diagnosis of trauma causing carpal tunnel syndrome are : 
-occupational trauma
-luxation 
-colles’ fracture
-scaphoid bone fracture
-crushing injury to flexor side of the wrist
-cut on flexor side of the wrist

​Differential diagnosis of tumours causing carpal tunnel syndrome are : 
-wrist ganglion 
benign tumour 
-hematoma 

​Differential diagnosis of carpal tunnel syndrome are : 
-tenosynovitis of flexor tendons
-idiopathic 
-fibrosis of flexor tendons
-trauma 
-endocrine causes
-metabolic causes
-tumour 
-granulomatous 
-pregnancy 
-rheumatology 
-congestive heart failure 

​Differential diagnosis of carotid bruit are : 
-hyperthyroidism 
-fever 
-vascular angioma of the skull 
-aortic coarctation 
-arteriosclerosis 
-aortic stenosis 
-thyroid artery dilation 
-arterial aneurysm 
-arteriovenous fistula 
-trauma to the carotid artery

​Differential diagnosis of endocrine / metabolic causes of secondary cardiomyopathy are : 
-hypokalemia 
-hypophosphatemia 
-hypomagnesemia 
-porphyria 
-oxalosis  
-gout 
-uremia 
-obesity 
-vitamin D overdose
-vitamin B and C deficiencies 
-selenium deficiency 
-niacin deficiency 
-diabetes mellitus 
-Cushing’s disease
-acromegaly 
-hyperparathyroidism 
-hypothyroidism 
-hyperthyroidism 
-thyroid tumours 
-adrenal tumours 
-pheochromocytoma 

​Differential diagnosis of allergic reaction causing secondary cardiomyopathy are : 
-drug induced allergen 
-cardiac transplant rejection 

​Differential diagnosis of infiltrative, granulomatous disorders causing secondary cardiomyopathy are : 
-wegener’s granulomatosis 
-granulomatous or giant cell myocarditis
-hemorchromatosis 
-amyloidosis 
-sarcoidosis 
-leukemia infiltration 
-angiomas
-myxomas
-rhabdomyomas 
-sarcoma 

​Differential diagnosis of neuromuscular causes of secondary cardiomyopathy are : 
-Refsum’s disease
-Friedreich’s ataxia 
-myotonic dystrophic 
-muscular dystrophy