- Haploidy
- Haploinsufficiency
- Haplotype
- Haplotype block
- Haplotype estimation
- Haplotypes
- Happiness
- Haptens
- Haptic perception
- Haptics
- Haptocorrin
- Haptoglobin
- Hard palate
- Hard problem of consciousness
- Hard tissue
- Hard x-rays
- Harderian gland
- Hardiness
- Hardy-Weinberg principle
- Harlequin syndrome
- Harm avoidance
- Harm reduction
- Harmala alkaloids
- Harmaline
- Harmalol
- Harmane
- Harmine
- Harmonic distortion
- Harmonic scalpel
- Harmonization
- Harpagophytum
- Harpagoside
- Harrington rod
- Harris-Benedict equation
- Hartmann procedure
- Hartmann's operation
- Hartnup disease
- Harvard step test
- Hash oil
- Hashimoto's encephalopathy
- Hashimoto's thyroiditis
- Hashimoto-Pritzker disease
- Hashish
- Hashitoxicosis
- Hassall's corpuscles
- Haustra
- Haverhill fever
- Haversian canals
- Hawkins-Kennedy test
- Hawthorne effect
- Hay fever
- Hayflick limit
- Hayling and Brixton tests
- Hazard Communication Standard
- Hazard analysis
- Hazard elimination
- Hazard ratio
- Hazardous Substances Data Bank
- Hazardous drugs
- Hazardous materials
- Hazardous waste
- Haze
- Hazelnuts
- HbA1c
- Hbegf
- HeLa
- Head
- Head and neck cancer
- Head circumference
- Head direction cells
- Head injury
- Head lice
- Head mirror
- Head of pancreas
- Head shadow
- Head tilt chin lift
- Head transplant
- Head up display
- Head-mounted displays
- Head-twitch response
- Headaches
- Headphones
- Heaf test
- Healing
- Healing environment
- Health Action Process Approach
- Health Belief Model
- Health Informatics Service Architecture
- Health advocacy
- Health behavior
- Health care analytics
- Health care economics
- Health care efficiency
- Health care financing
- Health care policy
- Health claims
- Health crisis
- Health data
- Health disparity
- Health economics
- Health effects
- Health effects of pesticides
- Health effects of tobacco
- Health fairs
- Health humanities
- Health indicators
- Health inequality
- Health literacy
- Health occupations
- Health outcomes
- Health physics
- Health policy
- Health psychology
- Health risk assessment
- Health services
- Health services research
- Health system
- Health technology assessment
- Healthcare Effectiveness Data and Information Set
- Healthcare practitioner
- Healthcare providers
- Healthcare proxy
- Healthcare-associated pneumonia
- Healthy Life Years
- Healthy narcissism
- Healthy user bias
- Hearables
- Hearing
- Hearing Voices Movement
- Hearing aids
- Hearing loss
- Hearing protection device
- Hearing range
- Hearing tests
- Heart
- Heart Protection Study
- Heart arrhythmia
- Heart attack
- Heart beat
- Heart block
- Heart catheterization
- Heart contraction
- Heart development
- Heart disease
- Heart diseases
- Heart failure
- Heart failure with reduced ejection fraction
- Heart lung machine
- Heart murmurs
- Heart rate