- Taenia saginata and taenia solium
- Talipes
- Tamiflu
- Tapeworm infections
- Tau protein test
- Tay-Sachs disease
- TB
- Td/IPV vaccination
- Teeth grinding
- Teething
- Telogen effluvium
- Tendon repair, hand
- Tendonitis
- Tennis elbow
- Tenosynovitis
- TENS (transcutaneous electrical nerve stimulation)
- Termination of pregnancy
- Testicles, undescended
- Testicular cancer
- Testicular feminisation syndrome
- Testicular lumps and swellings
- Tetanus
- Thalassaemia
- Thirst
- Threadworms
- Thrombosis
- Thrush, men
- Thrush, oral - adults
- Thrush, oral - babies
- Thrush, vaginal
- Thyroid cancer
- Thyroid, overactive
- Thyroid, underactive
- TIA
- TIBC test
- Tick-borne encephalitis
- Tics
- Tietze's syndrome
- Tinea capitis
- Tinea corporis
- Tinea cruris
- Tinea pedis
- Tinnitus
- Toe, broken
- Tongue-tie
- Tonsillitis
- Tooth abscess
- Tooth decay
- Toothache
- Torticollis
- Total protein test
- Tourette's syndrome
- Toxic shock syndrome
- Toxocariasis
- Toxoplasmosis
- TPMT test
- Tracheostomy
- Trachoma
- Traction
- Transcutaneous electrical nerve stimulation (TENS)
- Transient ischaemic attack (TIA)
- Transsexualism
- Transurethral resection of the prostate
- Travel health
- Travel sickness
- Travel vaccinations
- Travellers' diarrhoea
- Tremor (essential)
- Trichomonas vaginalis
- Trichomoniasis
- Trichotillomania
- Trigeminal neuralgia
- Trigger finger
- Trophoblastic disease
- Tuberculosis (TB)
- Tuberous sclerosis
- Tummy ache
- Turner syndrome
- Transurethral resection of the prostate (TURP)
- Twisted neck
- Typhoid fever