A
- A fib
- AAT deficiency
- AATD
- Abdominal aortic aneurysm
- Abnormally excessive sweating
- Abscess, Bartholin’s
- Absence seizure
- Acanthosis nigricans
- Achalasia
- Achilles tendinitis
- Achilles tendon rupture
- Acid reflux, infant
- ACL injury
- Acne
- Acne inversa
- Acoustic neuroma (vestibular schwannoma)
- Acquired immunodeficiency syndrome
- Acromegaly
- Actinic keratosis
- Acute coronary syndrome
- Acute flaccid myelitis (AFM)
- Acute granulocytic leukemia
- Acute inflammatory demyelinating polyneuropathy
- Acute kidney failure
- Acute kidney injury
- Acute liver failure
- Acute lymphoblastic leukemia
- Acute lymphocytic leukemia
- Acute lymphoid leukemia
- Acute myeloblastic leukemia
- Acute myelogenous leukemia
- Acute myeloid leukemia
- Acute nonlymphocytic leukemia
- Acute radiation sickness
- Acute radiation syndrome
- Acute renal failure
- Acute respiratory distress syndrome
- Acute rhinosinusitis
- Acute sinusitis
- Acute symptomatic seizures secondary to autoimmune encephalitis
- Addiction, alcohol
- Addiction, gambling
- Addiction, nicotine
- Addison’s disease
- Adenitis, mesenteric
- Adenomyosis
- ADHD in children
- ADHD, Adult
- Adhesive capsulitis
- Adjustment disorders
- Adnexal tumors and masses
- Adolescent schizophrenia
- Adrenal cancer
- Adrenal mass
- Adrenoleukodystrophy
- Adult attention-deficit/hyperactivity disorder (ADHD)
- Adult Still disease
- AE
- AFM
- Age spots (liver spots)
- Age-related macular degeneration, dry
- Age-related macular degeneration, wet
- Agnogenic myeloid metaplasia
- Agoraphobia
- AIDP
- AIDS/HIV
- Airplane ear
- Albinism
- ALCL
- Alcohol addiction
- Alcohol intolerance
- Alcohol poisoning
- Alcohol use disorder
- Alcohol-associated hepatitis
- Alcoholic hepatitis (Alcohol-associated hepatitis)
- Allergic granulomatosis
- Allergic granulomatosis and angiitis
- Allergic rhinitis
- Allergies
- Allergy, dust mite
- Allergy, egg
- Allergy, food
- Allergy, latex
- Allergy, milk
- Allergy, mold
- Allergy, nickel
- Allergy, peanut
- Allergy, penicillin
- Allergy, pet
- Allergy, shellfish
- Allergy, wheat
- Alopecia
- Alpha 1
- Alpha-1-antitrypsin deficiency
- Alpha-gal syndrome
- ALS
- Alveolar osteitis
- Alzheimer’s disease
- Ambiguous genitalia
- Amblyopia
- Ameloblastoma
- Amenorrhea
- American trypanosomiasis
- Amnesia
- Amnesia, transient global
- Amnestic syndrome
- Ampullary cancer
- Amyloid disease
- Amyloidosis
- Amyotrophic lateral sclerosis (ALS)
- Anal cancer
- Anal fissure
- Anal fistula
- Anal itching
- Anaphylaxis
- Anaplastic large cell lymphoma
- Anemia
- Anemia, aplastic
- Anemia, Cooley’s
- Anemia, iron deficiency
- Anemia, Mediterranean
- Anemia, sickle cell
- Anemia, vitamin deficiency
- Aneurysm, abdominal aortic
- Aneurysm, aortic
- Aneurysm, brain
- Aneurysm, popliteal artery
- Aneurysm, thoracic aortic
- Aneurysms
- Angelman syndrome
- Angiitis
- Angina
- Angina pectoris
- Angioblastoma
- Angioedema and hives
- Angiofollicular lymph node hyperplasia
- Angiosarcoma
- Ankle fracture
- Ankle sprain
- Ankyloglossia
- Ankylosing spondylitis
- Anorexia
- Anorexia nervosa
- Anorgasmia in women
- Anterior cruciate ligament injury
- Anterior vaginal prolapse
- Anterior vaginal prolapse (cystocele)
- Anthrax
- Antibiotic-associated colitis
- Antibiotic-associated diarrhea
- Antiphospholipid syndrome
- Antisocial personality disorder
- Anxiety disorder, generalized
- Anxiety disorder, social
- Anxiety disorders
- Aortic aneurysm
- Aortic aneurysm, abdominal
- Aortic coarctation
- Aortic dissection
- Aortic insufficiency
- Aortic regurgitation
- Aortic valve disease
- Aortic valve regurgitation
- Aortic valve stenosis
- APD
- Aphasia
- Aphasia, primary progressive
- Aphthous stomatitis
- Aphthous ulcer
- Apical ballooning syndrome
- Aplastic anemia
- Appendicitis
- Appendix cancer
- APS
- ARDS
- Arenaviruses
- Argentine hemorrhagic fever
- Arm fracture
- Arnold-Chiari malformation
- Arrhythmia
- Arteriosclerosis / atherosclerosis
- Arteriovenous fistula
- Arteriovenous malformation
- Arteritis, giant cell
- Arteritis, Takayasu’s
- Arthritis
- Arthritis, basal joint
- Arthritis, degenerative
- Arthritis, gouty
- Arthritis, infectious
- Arthritis, juvenile idiopathic
- Arthritis, osteoarthritis
- Arthritis, psoriatic
- Arthritis, reactive
- Arthritis, rheumatoid
- Arthritis, septic
- Arthritis, thumb
- Asbestosis
- Ascariasis
- Ascites
- ASD
- Aseptic necrosis
- Aspergillosis
- Asthma
- Asthma attack
- Asthma, childhood
- Asthma, exercise-induced
- Asthma, occupational
- Astigmatism
- Astrocytoma
- AT
- Ataxia
- Atelectasis
- Atherosclerosis
- Athlete’s foot
- Atopic dermatitis (eczema)
- Atresia of bile ducts
- Atrial fibrillation
- Atrial flutter
- Atrial septal defect (ASD)
- Atrial tachycardia
- Atrioventricular canal defect
- Atrioventricular nodal reentry tachycardia (AVNRT)
- Atrioventricular septal defect
- Atrophic vaginitis
- ATRT
- Attachment disorder
- Attention-deficit/hyperactivity disorder (ADHD) in children
- Attention-deficit/hyperactivity disorder in adults
- Atypical genitalia
- Atypical hyperplasia of the breast
- Atypical teratoid rhabdoid tumor (ATRT)
- Atypical teratoid/rhabdoid tumor brain cancer
- Auditory information processing disorder
- Auditory processing disorder
- Autism spectrum disorder
- Autoimmune associated epilepsy
- Autoimmune encephalitis
- Autoimmune encephalopathy
- Autoimmune epilepsy
- Autoimmune hepatitis
- Autoimmune pancreatitis
- Autonomic neuropathy
- Avascular necrosis (osteonecrosis)
- Avian influenza
- AVN
- AVNRT