- Secondary - see also condition
- Secretan's disease or syndrome (posttraumatic edema) 782.3
- Secretion
- Section
- Seeligmann's syndrome (ichthyosis congenita) 757.1
- Segmentation, incomplete (congenital) - see also Fusion
- Seizure 780.39
- Self-mutilation 300.9
- Semicoma 780.09
- Semiconsciousness 780.09
- Seminal
- Seminoma (M9061/3)
- Semliki Forest encephalitis 062.8
- Senear-Usher disease or syndrome (pemphigus erythematosus) 694.4
- Senecio jacobae dermatitis 692.6
- Senectus 797
- Senescence 797
- Senile (see also condition) 797
- Senility 797
- Sensation
- Sense loss (touch) (see also Disturbance, sensation) 782.0
- Sensibility disturbance NEC (cortical) (deep) (vibratory) (see also Disturbance, sensation) 782.0
