See Conditions by First Letter (T)
- T-Lymphocytopenia
- T-Lymphocytopenia, Idiopathic CD4-Positive
- Tachycardia
- Tachycardia, Atrioventricular Nodal Reentry
- Tachycardia, Ectopic Atrial
- Tachycardia, Ectopic Junctional
- Tachycardia, Paroxysmal
- Tachycardia, Sinus
- Tachycardia, Supraventricular
- Tachycardia, Ventricular
- Taeniasis
- Takayasu Arteritis
- Takotsubo Cardiomyopathy
- Talipes Equinovarus
- Tangier Disease
- Taste Disorders
- Tauopathies
- Tay-Sachs Disease
- Telangiectasia, Hereditary Hemorrhagic
- Telangiectasis
- Temporomandibular Joint Disorders
- Temporomandibular Joint Dysfunction Syndrome
- Tendinopathy
- Tendon Entrapment
- Tendon Injuries
- Tennis Elbow
- Tenosynovitis
- Tension-Type Headache
- Teratoma
- Testicular Cancer
- Testicular Diseases
- Testicular Hydrocele
- Testicular Neoplasms
- Testotoxicosis
- Tetanus
- Tetany
- Tetrahydrobiopterin Deficiency
- Tetralogy of Fallot
- Thalassemia
- Thiamine Deficiency
- Thinness
- Thoracic Diseases
- Thoracic Injuries
- Thoracic Neoplasms
- Thoracic Outlet Syndrome
- Thrombasthenia
- Thromboangiitis Obliterans
- Thrombocythemia, Essential
- Thrombocytopenia
- Thrombocytosis
- Thromboembolism
- Thrombophilia
- Thrombophlebitis
- Thrombosis
- Thrombotic Microangiopathies
- Thrombotic Thrombocytopenic Purpura, Acquired
- Thrombotic Thrombocytopenic Purpura, Congenital
- Thymic Epithelial Tumor
- Thymoma
- Thymus Neoplasms
- Thyroid Cancer, Anaplastic
- Thyroid Cancer, Follicular
- Thyroid Cancer, Medullary
- Thyroid Diseases
- Thyroid Neoplasms
- Thyroid Nodule
- Thyroiditis
- Thyroiditis, Autoimmune
- Thyrotoxic Periodic Paralysis
- Thyrotoxicosis
- Tibial Fractures
- Tibial Neuropathy
- Tic Disorders
- Tick-Borne Diseases
- Tick-borne Encephalitis
- Tics
- Tinea
- Tinea Capitis
- Tinea Pedis
- Tinea Versicolor
- Tinnitus
- Tissue Adhesions
- Tobacco Use Disorder
- Tongue Cancer
- Tongue Neoplasms
- Toni-Debre-Fanconi Syndrome
- Tonsillitis
- Tooth Abnormalities
- Tooth Abrasion
- Tooth Attrition
- Tooth Demineralization
- Tooth Discoloration
- Tooth Diseases
- Tooth Erosion
- Tooth Fractures
- Tooth Injuries
- Tooth Loss
- Tooth Mobility
- Tooth Wear
- Tooth, Impacted
- Tooth, Nonvital
- Tooth, Supernumerary
- Toothache
- Torsades de Pointes
- Torsion Abnormality
- Torticollis
- Tourette Syndrome
- Toxemia
- Toxic Epidermal Necrolysis
- Toxocariasis
- Toxoplasmosis
- Toxoplasmosis, Cerebral
- Toxoplasmosis, Congenital
- Toxoplasmosis, Ocular
- Tracheal Neoplasms
- Tracheal Stenosis
- Tracheitis
- Tracheobronchomalacia
- Tracheoesophageal Fistula
- Tracheomalacia
- Trachoma
- Transitional Cell Carcinoma
- Translocation, Genetic
- Transposition of Great Vessels
- Transposition of the Great Arteries
- Transsexualism
- Transverse Myelitis
- Trauma, Nervous System
- Tremor
- Tremor Hereditary Essential, 1
- Treponema Infection
- Treponemal Infections
- Trichiasis
- Trichomonas Infections
- Trichomonas Vaginitis
- Trichothiodystrophy Syndromes
- Trichotillomania
- Trichuriasis
- Tricuspid Atresia
- Tricuspid Valve Insufficiency
- Trigeminal Neuralgia
- Trigger Finger Disorder
- Trigger Thumb
- Trismus
- Trisomy
- Trisomy 13
- Trisomy 18
- Trophoblastic Neoplasms
- Tropical Sprue
- Truncus Arteriosus, Persistent
- Trypanosomiasis
- Trypanosomiasis, African
- Trypanosomiasis, Human East-African
- Tuberculosis
- Tuberculosis, Central Nervous System
- Tuberculosis, Lymph Node
- Tuberculosis, Meningeal
- Tuberculosis, Miliary
- Tuberculosis, Multidrug-Resistant
- Tuberculosis, Osteoarticular
- Tuberculosis, Pleural
- Tuberculosis, Pulmonary
- Tuberculous Meningitis
- Tuberous Sclerosis
- Tubular Aggregate Myopathy
- Tufted Angioma
- Tufting Enteropathy
- Tularemia
- Tumor Lysis Syndrome
- Tumor Virus Infections
- Turner Syndrome
- Twin Twin Transfusion Syndrome
- Tylosis
- Tympanic Membrane Perforation
- Typhoid Fever
- Typhus
- Typhus, Epidemic Louse-Borne
- Tyrosinemia Type 1
- Tyrosinemias