- Calculus, calculi, calculous 592.9
- Caliectasis 593.89
- California
- Caligo cornea 371.03
- Callositas, callosity (infected) 700
- Callus (infected) 700
- Calvé (-Perthes) disease (osteochondrosis, femoral capital) 732.1
- Calvities (see also Alopecia) 704.00
- Cameroon fever (see also Malaria) 084.6
- Camptocormia 300.11
- Camptodactyly (congenital) 755.59
- Camurati-Engelmann disease (diaphyseal sclerosis) 756.59
- Canal - see condition
- Canaliculitis (lacrimal) (acute) 375.31
- Canavan's disease 330.0
- Cancer (M8000/3)-see also Neoplasm, by site, malignant
- Cancerous (M8000/3 - see Neoplasm, by site, malignant
- Cancerphobia 300.29
- Cancrum oris 528.1
- Candidiasis, candidal 112.9
- Candidiosis - see Candidiasis
- Candiru infection or infestation 136.8