​Differential diagnosis of Right Sided Congestive Heart Failure: 
-nephrotic syndrome 
-peripheral venous insufficiency 
-cirrhosis 
-chronic obstructive pulmonary disease

​Differential diagnosis of high output heart failure causing Congestive Heart Failure: 
-carcinoid 
-sepsis 
-hepatic hemangiomatosis 
-beri beri 
-Paget’s disease of the bone 
-arteriovenous shunting 
-severe asthma 
-hyperthyroidism 

​Differential diagnosis of dystolic dysfunction causing Congestive Heart Failure: 
-diabetes 
-restrictive cardiomyopathy 
-hypertrophic obstructive cardiomyopathy 
-hypertension 
-left ventricular hypertrophy 

​Differential diagnosis of causes of right ventricular failure causing Congestive Heart Failure: 
-right sided valve disease
-chronic pulmonary embolism 
-cor pulmonale
-left ventricular failure 

​Differential diagnosis of causes of left ventricular failure causing Congestive heart failure: 
-Chagas’ disease
-High Output states 
-arrhythmias such as atrial fibrillation 
-volume overload including thiazolidinediones such as rosiglitazone 
-aortic stenosis 
-mitral regurgitation 
-aortic insufficiency 
-idiopathic cardiomyopathy 
-alcoholic cardiomyopathy 
-hypertension 
-ischemic cardiomyopathy 

​Differential diagnosis of Congestive Heart Failure: 
-myxedema / hypothyroidism 
-nephrotic syndrome 
-peripheral venous insufficiency 
-cirrhosis 
-pneumonia 
-chronic obstructive pulmonary disease

​Differential diagnosis of viral causes of Community Acquired Pneumonia: 
-Parainfluenza virus 
-Adenovirus 
-Respiratory syncytial virus 
-Influenza virus 

​Differential diagnosis of bacterial causes of Community Acquired Pneumonia: 
-legionella 
-Klebsiella pneumoniae
-Moraxella catarrhalis 
-Neisseria meningitides
-Staphylococcus aureus 
-Chlamydia pneumoniae 
-Mycoplasma pneumoniae 
-Haemophilus influenzae
-Streptococcus pneumoniae 

​Differential diagnosis of Community Acquired Pneumonia : 
-bronchiolitis
-bronchiolitis obliterans with organizing pneumonia 
-hypersensitivity pneumonitis 
-lung neoplasm 
-sarcoidosis 
-myocardial infarction 
-pulmonary embolism 
-tuberculosis 
-lung abscess
-bronchitis 
-pnenumocystis pneumonia 
-aspiration pneumonia 
-viral pneumonia 
-bacterial pneumonia 

​
Differential diagnosis of Common Variable Immunodeficiency: 
-immunodeficiency with thymoma
-X linked agammaglobulinemia 
-systemic lupus erythematosus 
-celiac sprue 
-asplenism 
-cystic fibrosis 
-multiple myeloma 
-selective IgA deficiency 
-secondary immunodeficiency such as leukemia, corticosteroids, AIDS,