haem- or haema- or haemo- See: hem-.

haemat- or haemato- See: hem-.

hallucin- or hallucino- [from Latin allucinari to prate, to dream] Denotes false perception (hallucinogen).

hapl- or haplo- (also apl- or aplo-) [from Greek haploeides single] (1) single, simple (haploid); (2) denoting the haploid condition (haplotype).

hect- or hecto- [from Greek hekaton a hundred] A hundred — used in metric measure (hectare, hectoliter).

hedy- or hedys- [from Greek hedys sweet] In taxonomic names: Sweet (Hedysarum).

heli- or helio- [from Greek helios sun] Denotes the sun, or sunlight (heliotropism).

helic- or helico- [from Greek helix spiral] Helix (helicase).

helminth- or helmintho- [from Greek helmis parasitic worm] Denotes parasitic worms, especially tapeworms and flatworms (helminthiasis, Platyhelminthes).

hem- or heme- or hemi- or hemo- or hemat- or hemato- (British spellings: haem- or haemo- or haemat- or haemato-) [from Greek aima blood] Denotes blood (hemoclasia, hemoglobin, hemoptysis, hemotoxin).

hemi- [from Greek hemi- half-] Half (hemizygote).

hendec- See: undec-.

hepa- or hepat- or hepato- [from Greek epar liver] Liver (hepatitis, hepatomegaly, hepatorrhexis).

herpet- or herpeto- [from Greek herpetos crawling, creeping] (1) denotes reptile(s) (herpetology); (2) denotes herpes (herpetic).

hetero- [from Greek eteros other] Other; indicating dissimilarity (heterosporous, heterotroph, heterozygote).

hidr- or hidro- [from Greek idros sweat] Denotes sweat (hidradenoma, hidroschesis).

hist- or histo- or histi- or histio- [from Greek istos tissue] Denotes tissue (histamine, histology, histotome, histotomy).

hol- or holo- [from Greek ilos whole] Complete, whole, unsegmented (holarctic, holometabolous).

hom- or homo- or homeo- [from Greek homos same] Same, similar (homogametic, homolog, homotaxis, homozygote).

humer- or humero- [from Latin humerus upper arm, shoulder] Denotes the humerus (humeroulnar).

hyal- or hyalo- [from Greek yalos glass] (1) transparent (hyaline); (2) pertaining to the vitreous humor (hyaloiditis).

hydr- or hydra- or hydro- [from Greek ydor water] (1) relating to water (hydrocephalic); (2) containing hydrogen (hydrocarbon).

hyo- [from Greek yoeides U-shaped — the hyoid is U-shaped] Pertaining to the hyoid bone (hyoepiglottic).

hyp- or hyph- or hypo- [from Greek ypo under] Under, beneath, low (hypochondriac, hypochromia, hypogeal, hypoxanthine).

hyper- [from Greek yper above] Over, above, beyond (hypercalcemia, hyperglycemia, hyperosmotic, hyperostosis, hyperphoria, hypertension).

hyps- or hypso- [from Greek ypsi high] Height, elevation (hypsodont).

hyster- or hystero- [from Greek ystera uterus] Denotes the uterus (hysterectomy, hysterorrhexis, hysterotrismus).