- Infliximab
- Influenza
- Influenza A
- Influenza A virus
- Influenza B
- Influenza C virus
- Influenza vaccine
- Influenza virus
- Influenza-like illness
- Infodemiology
- Informant Questionnaire on Cognitive Decline in the Elderly
- Information cascades
- Information processing
- Informed assent
- Informed consent
- Informed refusal
- Infraclavicular fossa
- Infracyanine green
- Infrahyoid muscle
- Infralimbic cortex
- Inframammary fold
- Infraorbital artery
- Infraorbital canal
- Infraorbital foramen
- Infraorbital groove
- Infraorbital margin
- Infraorbital nerve
- Infrapatellar fat pad
- Infrared detectors
- Infrared imaging
- Infrared laser
- Infrared radiation
- Infrared sauna
- Infraspinatus
- Infraspinatus muscle
- Infraspinous fossa
- Infratemporal fossa
- Infratemporal space
- Infratentorial region
- Infratrochlear nerve
- Infundibulum
- Infusion
- Infusion pump
- Infusion set
- Infusion therapy
- Ingenol mebutate
- Ingestion
- Ingestive behaviors
- Ingression
- Ingrown nail
- Ingrown toenails
- Inguinal canal
- Inguinal hernia
- Inguinal ligament
- Inguinal lymph node
- Inguinal lymphadenopathy
- Inguinal orchiectomy
- Inguinal region
- Inguinofemoral lymphadenectomy
- Inhalable insulin
- Inhalant abuse
- Inhalants
- Inhalation
- Inhalation exposure
- Inhalational anesthetics
- Inhalational anthrax
- Inhalers
- Inheritance
- Inhibin
- Inhibin B
- Inhibition
- Inhibitor of DNA-binding protein
- Inhibitor protein
- Inhibitors
- Inhibitory control
- Inhibitory postsynaptic potential
- Iniencephaly
- Inion
- Initial volume of distribution
- Initiation factors
- Injection port
- Injection site pain
- Injection site reaction
- Injections
- Injector pen
- Injury prevention
- Innate immune cells
- Innate immune responses
- Innate immune system
- Innate immunity
- Innate lymphoid cells
- Inner cell mass
- Inner critic
- Inner ear
- Inner enamel epithelium
- Inner hair cells
- Inner limiting membrane
- Inner membrane
- Inner mitochondrial membrane
- Inner nuclear layer
- Inner plexiform layer
- Inner root sheath
- Innervation
- Inoculation
- Inoculation needle
- Inoculum
- Inonotus obliquus
- Inorganic acids
- Inorganic carbon
- Inorganic chemicals
- Inorganic chemistry
- Inorganic compounds
- Inorganic phosphate
- Inorganic pyrophosphatase
- Inosine
- Inosine-5′-monophosphate dehydrogenase
- Inosinic acid
- Inositol
- Inositol 1 4 5 trisphosphate
- Inositol phosphate
- Inositol polyphosphate-5-phosphatase
- Inositol trisphosphate
- Inositol trisphosphate receptor
- Inositol-polyphosphate 5-phosphatase
- Inotersen
- Inotropes
- Inotropic
- Inotuzumab ozogamicin
- Inovirus
- Inquest
- Insanity
- Insanity defense
- Insect bite
- Insect repellent
- Insect vector
- Insecticides
- Insemination
- Insertion sequences
- Insertional mutagenesis
- Insight-oriented psychotherapy
- Insomnia
- Inspiratory reserve volume
- Instantaneous wave-free ratio
- Institute for Quality and Efficiency in Health Care
- Institutionalization
- Instructional design
- Instrument myopia
- Instrumental conditioning
- Instrumentation
- Insufflation