Diagnosaurus
- Café au lait spots
- Calcium, decreased serum
- Calcium, increased serum
- Calcium pyrophosphate deposition disease
- Campylobacter enteritis
- Cancer
- Cancer, bladder
- Cancer, bone
- Cancer, breast (female)
- Cancer, breast (male)
- Cancer, cervical
- Cancer, colorectal
- Cancer, endometrial
- Cancer, esophageal
- Cancer, gastric
- Cancer, liver
- Cancer, lung
- Cancer, oral
- Cancer, ovarian
- Cancer, pancreatic
- Cancer, paraneoplastic syndromes
- Cancer, prostate
- Cancer, renal cell
- Cancer, small intestine
- Cancer, testicular
- Cancer, thyroid
- Cancer, vulvar
- Cancer of unknown primary
- Candidiasis, cutaneous
- Candidiasis, disseminated
- Candidiasis, esophageal
- Candidiasis, oral
- Candidiasis, vulvovaginal
- Canker sore
- Carbon monoxide poisoning
- Carbuncles
- Carcinoma, basal cell
- Carcinoma, squamous cell
- Cardiac tamponade
- Cardiac tumors
- Cardiomyopathy, hypertrophic obstructive (HOCM)
- Cardiomyopathy, primary dilated
- Cardiomyopathy, restrictive
- Carotid artery aneurysm
- Carotid dissection
- Carpal tunnel syndrome
- Cataract
- Catatonia or stiffness
- Cat-scratch disease
- Cavitary lung disease
- Celiac sprue
- Cellulitis
- Cerebrovascular accident
- Cervical cancer
- Cervicitis
- Chagas' disease
- Chalazion
- Chancroid
- Charcot joint
- Cheilitis, angular
- Chemical warfare agents
- CHF
- CHF, right-sided
- Chickenpox
- Chlamydia urethritis & cervicitis
- Cholangitis
- Cholangitis, sclerosing
- Cholecystitis, acute
- Choledocholithiasis
- Cholelithiasis
- Cholera
- Cholestasis
- Cholesterol decreased
- Cholesterol increased
- Cholinergic poisoning
- Chondrocalcinosis
- Chorea
- Chronic diarrhea
- Chronic lymphocytic leukemia
- Chronic myelogenous leukemia
- Chronic obstructive pulmonary disease
- Chronic pain disorder
- Chronic venous insufficiency
- Churg-Strauss syndrome
- Cirrhosis
- Cirrhosis, biliary
- CLL
- Clonorchiasis (Chinese liver fluke)
- Clostridial myonecrosis
- CML
- CMV infection
- Coarctation of the aorta
- Cocaine intoxication
- Coccidioidomycosis
- Cold sore
- Cold urticaria
- Colitis, antibiotic-associated
- Colitis, ischemic
- Colitis, ulcerative
- Colonic polyps
- Colonic pseudo-obstruction, acute
- Colorectal cancer
- Coma
- Common variable immunodeficiency
- Community-acquired pneumonia
- Complex regional pain syndrome
- Conduction block, atrioventricular
- Condyloma acuminata
- Congestive heart failure
- Congestive heart failure, right-sided
- Conjunctivitis
- Constipation
- Constrictive pericarditis
- Contact dermatitis
- Conversion disorder
- COPD
- Corneal ulcer or inflammation
- Cor pulmonale
- Cortisol excess
- Cough headache
- CPPD
- Creutzfeldt-Jakob disease
- Crohn's disease
- Cryoglobulinemia
- Cryptococcal meningitis
- Cryptosporidiosis
- Cushing's syndrome
- Cutaneous candidiasis
- Cutaneous T cell lymphoma
- CXR, lower lobe disease
- CXR, upper lobe disease
- Cyclosporiasis
- Cysticercosis
- Cystic fibrosis
- Cystic hydatid disease
- Cystitis, acute
- Cytomegalovirus infection