Africa 
China 
Japan 
MENA 
- Localized surface plasmon resonance
- Lochia
- Lock-in amplifier
- Lockdowns
- Locked nucleic acid
- Locked-in syndrome
- Lockwood's ligament
- Locomotor ataxia
- Locus ceruleus
- Locus coeruleus
- Locus control region
- Locus heterogeneity
- Locus of control
- Locus of enterocyte effacement
- Locust
- Locust bean gum
- Lod score
- Lodoxamide
- Loewe additivity
- Loeys-Dietz syndrome
- Lofentanil
- Lofexidine
- Lofgren syndrome
- Log rank test
- LogMAR
- LogMAR chart
- LogP
- Loganic acid
- Loganin
- Logorrhea
- Logotherapy
- Logrank test
- Lombard effect
- Lomefloxacin
- Lomitapide
- Lomustine
- Lonafarnib
- Lonaprisan
- Loneliness
- Long COVID
- Long QT syndrome
- Long acting insulin
- Long bone
- Long chain fatty acid
- Long chain fatty acids
- Long ciliary nerve
- Long ciliary nerves
- Long covid
- Long non-coding RNAs
- Long noncoding RNA
- Long plantar ligament
- Long spine board
- Long term care
- Long term depression
- Long term memory
- Long terminal repeats
- Long thoracic nerve
- Long-acting reversible contraception
- Long-acting reversible contraceptives
- Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency
- Long-chain 3-hydroxyacyl-coenzyme a dehydrogenase deficiency
- Long-lived fission products
- Long-lived plasma cells
- Long-term care insurance
- Long-term depression
- Long-term memory
- Long-term nonprogressor
- Long-term potentiation
- Longevity
- Longifolene
- Longissimus
- Longitudinal data
- Longitudinal erythronychia
- Longitudinal fissure
- Longitudinal intestinal lengthening and tailoring
- Longitudinal studies
- Longitudinal study
- Longus capitis
- Longus capitis muscle
- Longus colli
- Longus colli muscle
- Lonicera japonica
- Lonidamine
- Looking-glass self
- Lookism
- Loop diuretics
- Loop mediated isothermal amplification
- Loose connective tissue
- Loperamide
- Lopinavir
- Loprazolam
- Loquat
- Loratadine
- Lorazepam
- Lorcaserin
- Lordosis
- Lordosis behavior
- Lorenzo's oil
- Loricrin
- Lorlatinib
- Lormetazepam
- Lornoxicam
- Los Angeles Prehospital Stroke Screen
- Losartan
- Losartan potassium
- Loss aversion
- Loss of appetite
- Loss of consciousness
- Loss of function mutation
- Loss of heterozygosity
- Loss of libido
- Lost to follow-up
- Loteprednol
- Lotion
- Lotus seeds
- Loud music
- Louping ill
- Louping ill virus
- Louse
- Lovage
- Lovastatin
- Lovaza
- Low anterior hairline
- Low back pain
- Low birth weight
- Low carbohydrate diet
- Low copy repeats
- Low frustration tolerance
- Low intensity pulsed ultrasound
- Low level laser therapy
- Low molecular weight heparin
- Low platelet count
- Low pressure hydrocephalus
- Low-FODMAP diet
- Low-affinity nerve growth factor receptor
- Low-density lipoprotein
- Low-dose chemotherapy
- Low-dose naltrexone
- Low-grade fibromyxoid sarcoma
- Low-intensity pulsed ultrasound
- Low-protein diet
- Low-set ears
- Lowe syndrome
- Lower abdominal pain
- Lower anterior resection
- Lower eyelid
- Lower gastrointestinal bleeding
- Lower gastrointestinal tract
- Lower motor neuron
- Lower motor neuron lesions