- 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
- Lower segment caesarean section
- Lower subscapular nerve
- Lower urinary tract symptoms
- Loxapine
- Loxoprofen
- Loxoscelism
- Lozenges
- Lp-LpA2
- Lubiprostone
- Lubrication
- Lucid dreams
- Lucid interval
- Lucifer yellow
- Luciferase
- Luciferin
- Lucigenin
- Lucinactant
- Lugol's iodine
- Lujan-Fryns syndrome
- Luliconazole
- Lumbar arteries
- Lumbar artery
- Lumbar enlargement
- Lumbar lordosis
- Lumbar lymph nodes
- Lumbar nerve
- Lumbar plexus
- Lumbar puncture
- Lumbar region
- Lumbar spinal stenosis
- Lumbar spine
- Lumbar splanchnic nerves
- Lumbar triangle
- Lumbar vein
- Lumbar vertebrae
- Lumbosacral joint
- Lumbosacral plexus
- Lumbosacral trunk
- Lumbricals
- Lumbrokinase
- Lumefantrine
- Lumen
- Lumican
- Luminol
- Lumiracoxib
- Lumpectomy
- Lumpy jaw
- Lunasin
- Lunate
- Lund and Browder chart
- Lung
- Lung abscess
- Lung allocation score
- Lung biopsy
- Lung bud
- Lung cancer
- Lung cancer screening
- Lung cancer susceptibility
- Lung cavity
- Lung compliance
- Lung diseases
- Lung fields
- Lung hemorrhage
- Lung infarction
- Lung infection
- Lung lobectomy
- Lung microbiota
- Lung nodules
- Lung parenchyma
- Lung transplant
- Lung transplantation
- Lung ventilation
- Lung volumes
- Lung-on-a-chip
- Lupeol
- Lupus
- Lupus anticoagulant
- Lupus erythematosus
- Lupus nephritis
- Lupus pernio
- Lupus vulgaris
- Lurasidone
- Lurbinectedin