• Labial fusion

• Labyrinthitis and vestibular neuritis

• Lactate dehydrogenase (LDH) test

• Lactose intolerance

• Lambert-Eaton myasthenic syndrome

• Laparoscopy (keyhole surgery)

• Laryngeal (larynx) cancer

• Laryngitis

• Laser eye surgery and lens surgery

• Laxatives

• Lazy eye

• Learning disabilities

• Leg cramps

• Legionnaires' disease

• Leptospirosis (Weil's disease)

• Leukoplakia

• Lichen planus

• Lichen sclerosus

• Limping in children

• Lipoedema

• Lipoma

• Listeriosis

• Liver cancer

• Liver disease

• Liver transplant

• Local anaesthesia

• Long QT syndrome

• Long-sightedness

• Lost or changed sense of smell

• Low blood pressure (hypotension)

• Low blood sugar (hypoglycaemia)

• Low sex drive (loss of libido)

• Low sperm count

• Low white blood cell count

• Lumbar decompression surgery

• Lumbar puncture

• Lumps

• Lung cancer

• Lung health checks

• Lung transplant

• Lupus

• Lyme disease

• Lymphoedema