• Caesarean section

• Cancer

• Carbon monoxide poisoning

• Carcinoembryonic antigen (CEA) test

• Cardiac catheterisation and coronary angiography

• Cardiomyopathy

• Cardiovascular disease

• Carotid endarterectomy

• Carpal tunnel syndrome

• Cataract surgery

• Catarrh

• Cavernoma

• Cavernous sinus thrombosis

• Cellulitis

• Cerebral palsy

• Cervical cancer

• Cervical rib

• Cervical screening

• Cervical spondylosis

• Charcot-Marie-Tooth disease

• Charles Bonnet syndrome

• Chemotherapy

• Chest infection

• Chest pain

• Chiari malformation

• Chickenpox

• Chilblains

• Childhood cataracts

• Chipped, broken or cracked tooth

• Chiropractic

• Chlamydia

• Cholera

• Cholesteatoma

• Chorionic villus sampling

• Chronic kidney disease

• Chronic lymphocytic leukaemia

• Chronic myeloid leukaemia

• Chronic obstructive pulmonary disease (COPD)

• Chronic pancreatitis

• Chronic traumatic encephalopathy

• Circumcision in boys

• Circumcision in men

• Cirrhosis

• Cleft lip and palate

• Clinical trials

• Clostridium difficile (C. diff) infection

• Club foot

• Cluster headaches

• Coeliac disease

• Cold sores

• Colic

• Colonoscopy

• Colostomy

• Colour vision deficiency (colour blindness)

• Colposcopy

• Coma

• Common cold

• Compartment syndrome

• Complementary and alternative medicine

• Complex regional pain syndrome

• Congenital heart disease

• Conjunctivitis

• Consent to treatment

• Constipation

• Contact dermatitis

• Cornea transplant

• Corns and calluses

• Coronary angioplasty and stent insertion

• Coronary artery bypass graft

• Coronary heart disease

• Corticobasal degeneration

• Cosmetic procedures

• Costochondritis

• Cough

• Coughing up blood (blood in phlegm)

• Counselling

• COVID-19

• Cradle cap

• Craniosynostosis

• Creutzfeldt-Jakob disease

• Crohn's disease

• Croup

• CT scan

• Cushing's syndrome

• Cuts and grazes

• Cyclical vomiting syndrome

• Cyclospora

• Cyclothymia

• Cystic fibrosis

• Cystitis

• Cystoscopy

• Cytomegalovirus (CMV)