• C. diff
  • Cachexia (evaluation of)
  • CAD [coronary artery disease] (overview of)
  • CAH [congenital adrenal hyperplasia]
  • Calcinosis, CREST
  • Calcium disorders
  • Calcium pyrophosphate deposition
  • Campylobacter infection
  • Cancer, basal cell
  • Candida vaginitis
  • Candidal meningitis
  • Canker sores
  • CAP [community acquired pneumonia]
  • Car sickness
  • Carbon monoxide poisoning
  • Carcinoid syndrome
  • Cardiac arrest
  • Cardiac glycoside ingestion, plant-based
  • Cardiac tamponade
  • Cardiogenic shock
  • Carotid artery stenosis
  • Carpal tunnel syndrome
  • Castor bean ingestion
  • Cat bite
  • Cataplexy
  • Cataracts
  • Cauda equina syndrome
  • Cavernous sinus thrombosis
  • CDAD [Clostridium difficile-associated disease]
  • Celiac disease
  • Cellulitis
  • Cellulitis, periorbital and orbital
  • Central airway obstruction
  • Central hypothyroidism
  • Central sleep apnea
  • Cerebral aneurysm
  • Cerebral arteriovenous malformation
  • Cerebral palsy
  • Cerebrovascular accident
  • Cerumen impaction
  • Cervical cancer
  • Cervical dystonia, acquired
  • Cervical smear, abnormal
  • Cervical spine pain (evaluation of)
  • Cervicitis
  • CF [cystic fibrosis]
  • CFS [chronic fatigue syndrome]
  • CGD [chronic granulomatous disease]
  • Chagas disease
  • Chancroid
  • Charcot-Marie-Tooth disease
  • Cheloid
  • Chest wall pain
  • Chest wall, rib fracture
  • CHF [congestive heart failure]
  • Chickenpox
  • Chikungunya virus
  • Child abuse
  • Chlamydia pneumoniae infection
  • Chlamydia trachomatis
  • Chlamydophila pneumoniae
  • Chloasma
  • Cholangiocarcinoma
  • Cholecystitis
  • Cholelithiasis
  • Cholera
  • Cholestasis of pregnancy
  • Cholesteatoma
  • Cholesterol disorders
  • Cholinergic ingestion, plant-based
  • Chondromalacia patella
  • Chronic atrial fibrillation
  • Chronic congestive heart failure
  • Chronic fatigue syndrome
  • Chronic granulomatous disease
  • Chronic inflammatory demyelinating polyneuropathy
  • Chronic kidney disease
  • Chronic lymphocytic leukemia
  • Chronic myelogenous leukemia
  • Chronic myelogenous leukemia, blast crisis
  • Chronic obstructive lung disease
  • Chronic obstructive lung disease, acute exacerbation
  • Chronic pain syndromes
  • Chronic pancreatitis
  • Chronic pelvic pain in women
  • Chronic pyelonephritis
  • Chronic renal failure
  • Chronic renal insufficiency
  • Chronic sinusitis
  • Chronic venous insufficiency
  • Churg Strauss syndrome
  • Chylomicronemia
  • CIDP [chronic inflammatory demyelinating polyneuropathy]
  • CIN [cervical intraepithelial neoplasia]
  • Cirrhosis
  • CJD [Creutzfeldt-Jakob syndrome]
  • CKD
  • Claustrophobia
  • Cleft lip & palate
  • Climacteric syndrome
  • CLL [chronic lymphocytic leukemia]
  • Clostridium botulinum
  • Clostridium difficile-associated disease
  • Club foot
  • CML [chronic myelogenous leukemia]
  • CML, blast crisis
  • CMV [cytomegalovirus infection]
  • CNS neoplasia (overview of)
  • CNS neoplasm, astrocytic
  • CNS neoplasm, craniopharyngioma
  • CNS neoplasm, medulloblastoma
  • CNS neoplasm, meningioma
  • COAG [chronic open-angle glaucoma]
  • Coal worker's pneumoconiosis
  • Coarctation of the aorta
  • Cocaine overdose
  • Cocaine use disorder
  • Coccidioidal meningitis
  • Coccidioidomycosis
  • Coccygodynia
  • Coin lesion, pulmonary (evaluation of)
  • COLD [chronic obstructive lung disease]
  • COLD [chronic obstructive lung disease], acute
  • Cold sores
  • Colic, infantile
  • Colles fracture
  • Colon cancer
  • Colonic distention, toxic megacolon
  • Colonic ischemia
  • Colonic obstruction
  • Colonic polyps
  • Colonic polyps, familial adenomatous polyposis syndromes
  • Colonic polyps, Peutz-Jeghers syndrome
  • Colorectal cancer
  • Comedones
  • Common cold
  • Common cutaneous drug reactions
  • Common hereditary lysosomal storage diseases
  • Common toxic plant ingestions
  • Common warts
  • Community-acquired pneumonia
  • Compartment syndrome of extremities
  • Complement deficiencies
  • Complex regional pain syndrome
  • Concussion
  • Condyloma acuminata
  • Confusional state, acute (evaluation of)
  • Congenital adrenal hyperplasia
  • Congenital heart disease
  • Congenital megacolon
  • Congenital torticollis
  • Congestive heart failure acute exacerbation
  • Conn's disease
  • Constipation in adults
  • Constipation in children
  • Contact dermatitis
  • Contraception
  • Contusion
  • Conversion and somatic symptom disorders
  • COP [Cryptogenic organizing pneumonia]
  • COPD
  • Copper storage disease
  • Coral snake bite
  • Corneal abrasions
  • Corneal inflammation
  • Coronary artery disease
  • Costochondritis
  • Cough, hemoptysis (evaluation of)
  • Coxiella burnetii infection
  • Coxsackievirus infections
  • CP [cerebral palsy]
  • CPPD [calcium pyrophosphate dihydrate deposition]
  • Crabs
  • Crack cocaine abuse
  • Cradle cap
  • Crail syndrome
  • Cranial arteritis
  • Craniopharyngioma
  • CREST syndrome
  • Creutzfeldt Jakob syndrome
  • CRF [chronic renal failure]
  • Crib death
  • Crohn disease
  • Crotaline snake bite
  • Croup
  • CRPS [complex regional pain syndrome]
  • Cryoglobulinemia
  • Cryptococcal meningitis
  • Cryptococcosis
  • Cryptogenic organizing pneumonia
  • Cryptorchidism
  • Cryptosporidiosis
  • CTCL [Cutaneous T-cell lymphoma]
  • CTS [carpal tunnel syndrome]
  • CUP [cancer of unknown primary site]
  • Cushing syndrome
  • Cutaneous burns
  • Cutaneous larva migrans
  • Cutaneous T-cell lymphoma
  • CVA [cerebrovascular accident]
  • CVID [common variable immunodeficiency]
  • Cyanocobalamin deficiency
  • Cyanotic heart disease
  • Cyst, ovary
  • Cystic fibrosis
  • Cysticercosis
  • Cytomegalovirus infection