L
- Lactase deficiency
- Lactation mastitis
- Lactose intolerance
- Laryngitis
- Lassa fever
- Lateral elbow tendinopathy
- Lateral epicondylitis
- Lateral epicondylosis
- Latex allergy
- Lazy eye (amblyopia)
- LCIS
- Lead poisoning
- Left ventricular hypertrophy
- Leg fracture
- Legg-Calve-Perthes disease
- Legionellosis
- Legionnaires’ disease
- Leiomyosarcoma
- Lentigines, solar
- Leukemia
- Leukemia, acute lymphocytic
- Leukemia, acute myelogenous
- Leukemia, chronic lymphocytic
- Leukemia, chronic myelogenous
- Leukemia, general
- Leukemia, hairy cell
- Leukoplakia
- Lewy body dementia
- Lice
- Lice, body
- Lichen planus
- Lichen planus, oral
- Lichen sclerosus
- Lichen simplex chronicus
- Lip cancer
- Lipodystrophy, intestinal
- Lipoma
- Liposarcoma
- Listeria infection
- Listeriosis
- Liver cancer
- Liver disease
- Liver failure, acute
- Liver fibrosis
- Liver hemangioma
- Liver spots
- Liver, enlarged
- Lobular carcinoma in situ (LCIS)
- Localized scleroderma
- Lockjaw
- Long QT syndrome
- Loss of bladder control
- Lou Gehrig’s disease
- Low blood pressure (hypotension)
- Low blood sugar
- Low body temperature
- Low platelet count
- Low sex drive in women
- Low sperm count
- Low testosterone
- Low-flow priapism
- Lung cancer
- Lung collapse
- Lung disease, interstitial
- Lupus
- Lupus nephritis
- Lyme disease
- Lymph nodes, swollen
- Lymphadenitis
- Lymphadenitis, mesenteric
- Lymphedema
- Lymphoma
- Lymphoma, Hodgkin
- Lymphoma, non-Hodgkin
- Lymphoplasmacytic lymphoma
- Lynch syndrome