- Akr1c3
- Akrasia
- Alachlor
- Alacrima
- Alagebrium
- Alagille syndrome
- Alamethicin
- Alangium
- Alanine
- Alanine aminotransferase
- Alanine dehydrogenase
- Alanine racemase
- Alanine scanning
- Alanine transaminase
- Alar fascia
- Alar ligament
- Alarm clock
- Alarm fatigue
- Alarmin
- Alarmone
- Alaryngeal speech
- Albaconazole
- Albendazole
- Albendazole sulfoxide
- Albiglutide
- Albinism
- Albizia julibrissin
- Albizia lebbeck
- Albomycin
- Albright syndrome
- Albright's hereditary osteodystrophy
- Albumin
- Albuminuria
- Albuterol
- Alcaftadine
- Alcaligenes
- Alcaligenes faecalis
- Alcam
- Alchornea cordifolia
- Alcian blue
- Alcian blue stain
- Alclometasone
- Alcohol
- Alcohol abuse
- Alcohol and breast cancer
- Alcohol and cancer
- Alcohol and cardiovascular disease
- Alcohol consumption
- Alcohol dehydrogenase
- Alcohol dehydrogenases
- Alcohol dependence
- Alcohol detoxification
- Alcohol intolerance
- Alcohol intoxication
- Alcohol liver disease
- Alcohol metabolism
- Alcohol oxidase
- Alcohol septal ablation
- Alcohol use disorder
- Alcohol withdrawal
- Alcohol withdrawal delirium
- Alcohol withdrawal syndrome
- Alcohol-related brain damage
- Alcohol-related crime
- Alcohol-related dementia
- Alcohol-related liver disease
- Alcoholic beverage
- Alcoholic cardiomyopathy
- Alcoholic cirrhosis
- Alcoholic fatty liver
- Alcoholic fermentation
- Alcoholic hallucinosis
- Alcoholic hepatitis
- Alcoholic intoxication
- Alcoholic ketoacidosis
- Alcoholic liver disease
- Alcoholic neuropathy
- Alcoholic pancreatitis
- Alcoholic polyneuropathy
- Alcoholics Anonymous
- Alcoholism
- Alcohols
- Alcuronium
- Aldehyde dehydrogenase
- Aldehydes
- Aldesleukin
- Aldicarb
- Alditol
- Aldo-keto reductase
- Aldohexose
- Aldol
- Aldolase
- Aldolase C
- Aldolase b
- Aldonic acid
- Aldophosphamide
- Aldose
- Aldose reductase
- Aldose reductase inhibitors
- Aldosterone
- Aldosterone antagonists
- Aldosterone escape
- Aldosterone synthase
- Aldosterone to renin ratio
- Aldosterone-to-renin ratio
- Aldrin
- Aldurazyme
- Alectinib
- Alefacept
- Alemtuzumab
- Alendronate
- Alendronic acid
- Alertness
- Aleurone
- Alexa Fluor
- Alexander Technique
- Alexander disease
- Alexia
- Alexia without agraphia
- Alexithymia
- Alfalfa
- Alfaxalone
- Alfentanil
- Alfuzosin
- Alginate
- Alginate dressing
- Alginic acid
- Alglucerase
- Alglucosidase alfa
- Algor mortis
- Alicaforsen
- Alice in Wonderland syndrome
- Alicyclic compounds
- Alien hand syndrome
- Alienation
- Alimemazine
- Alimentary toxic aleukia
- Alimentation
- Aliphatic hydrocarbons
- Alipogene tiparvovec
- Alirocumab
- Aliskiren
- Alisma orientale
- Alisporivir
- Alistipes
- Alitame
- Alitretinoin
- Alizapride
- Alizarin
- Alizarin red s