- Hypostasis, pulmonary 514
- Hypostatic - see condition
- Hyposthenuria 593.89
- Hyposuprarenalism 255.41
- Hypotension (arterial) (constitutional) 458.9
- Hypothermia (accidental) 991.6
- Hypothymergasia (see also Psychosis, affective) 296.2
- Hypothyroidism (acquired) 244.9
- Hypotonia, hypotonicity, hypotony 781.3
- Hypotrichosis 704.09
- Hypotropia 378.32
- Hypoventilation 786.09
- Hypovitaminosis (see also Deficiency, vitamin) 269.2
- Hypovolemia 276.52
- Hypoxemia (see also Anoxia) 799.02
- Hypoxia (see also Anoxia) 799.02
- Hypoxic-ischemic encephalopathy (HIE) 768.70
- Hypsarrhythmia (see also Epilepsy) 345.6
- Hysteralgia, pregnant uterus 646.8
- Hysteria, hysterical 300.10
- Hysteroepilepsy 300.11
- Hysterotomy, affecting fetus or newborn 763.89