- B12 vitamin deficiency
- Babies, crying
- Babies, weaning
- Back pain
- Bacterial vaginosis
- Bad breath
- Baker's cyst
- Balanitis
- Balding
- Bariatric surgery
- Barium enema
- Bartholin's cyst
- BCG (tuberculosis) vaccination
- Bed sores
- Bedbugs
- Bedwetting
- Behçet’s disease
- Bell's palsy
- Benign prostatic hyperplasia
- Beta blockers
- Bicarbonate test
- Bile duct cancer
- Bilharzia
- Binge eating
- Biopsy
- Bipolar disorder
- Bird flu
- Birth control
- Birthmarks
- Bites
- Bites, human and animal
- Bites, insect
- Bites, snake
- Black eye
- Blackheads
- Bladder cancer
- Bladder infection
- Bladder stones
- Bleeding from the bottom
- Bleeding in the brain
- Blepharitis
- Blepharospasm
- Blindness
- Blisters
- Blood clot
- Blood donation
- Blood gases test
- Blood groups
- Blood in the stools
- Blood in the urine
- Blood poisoning
- Blood pressure (high)
- Blood pressure (low)
- Blood tests
- Blood transfusion
- Blushing
- Body odour
- Body piercing
- Boils
- Bone cancer (sarcoma)
- Bone cyst
- Bone densitometry scan
- Bone marrow donation
- Bone marrow transplant
- Borderline personality disorder
- Bottle feeding
- Botulism
- Bowel cancer
- Bowel incontinence
- Bowel transplant
- Braces (dental)
- Brain abscess
- Brain aneurysm
- Brain tumour
- Brain death
- Brain haemorrhage
- Brain injury
- Breast abscess
- Breast cancer (female)
- Breast cancer (male)
- Breast discharge
- Breast implants
- Breast lump
- Breast pain, cyclical
- Breast reduction
- Breastfeeding
- Breathing difficulty
- Breathlessness
- Brittle bones
- Broken ankle
- Broken arm
- Broken collarbone
- Broken finger
- Broken hip
- Broken nose
- Broken ribs
- Broken toe
- Broken tooth
- Broken wrist
- Bromhidrosis (body odour)
- Bromodosis (smelly feet)
- Bronchiectasis
- Bronchiolitis
- Bronchitis
- Bronchodilator medicines
- Bruised ribs
- Bruxism
- BSE
- Bulimia
- Bunion
- Burns and scalds
- Bursitis