Read about "male menopause", where some men develop depression, loss of sex drive, erectile dysfunction and other physical and emotional symptoms when they reach their late 40s to early 50s.
Find out about tight foreskin (phimosis), including what you can do to ease a tight foreskin and when to get medical help.
Read more about temporomandibular disorder (TMD), which is a problem affecting the chewing muscles and the joints between the lower jaw and the base of the skull.
NHS information and advice about tension headaches. Find out about symptoms, causes, treatments, prevention and when to get medical help.
Find out about tetanus, including how you get it, what the symptoms are, when to get medical help, how it’s treated and the tetanus vaccination.
Thrombophilia is a condition that increases your risk of blood clots. It’s usually treated with anticoagulant medicines.
Find out what a total iron-binding capacity (TIBC) or transferrin test measures and what high and low TIBC levels may indicate.
Find out about tongue-tie, including symptoms and treatments.
Read about the causes of toothache, when to see a dentist, and how toothache can be relieved and prevented.
Find out about tooth decay, including the symptoms, when to see a dentist, how it’s treated and how it can be prevented.
Topical corticosteroids (steroids) are medicines that are applied directly to the skin to reduce inflammation and irritation.
Find out about the health conditions a total protein test can help diagnose.
Find out about toxic shock syndrome (TSS), including what the symptoms are, when to get medical help and how it is treated.
Read about transcutaneous electrical nerve stimulation (TENS), a method of pain relief that involves the use of a mild electrical current.
Read more about trimethylaminuria which is an uncommon genetic disorder that causes a strong body odour, usually described as like rotting fish, poo or rubbish.
Find out about typhus, including how you get it, how to avoid getting it, what the symptoms are, where to get medical help, and how it's treated.
Find out about tailbone (coccyx) pain, including how to ease the pain yourself and when to get medical help. Read about symptoms, causes and treatments.
Tay-Sachs disease is a very rare and usually fatal genetic disorder that causes progressive damage to the nervous system.
Read about teeth grinding (bruxism). Find out what causes it, what the associated symptoms are, when to get medical help and how it can be treated.
Find out more about tendonitis, where a tendon becomes swollen. It can cause joint pain and stiffness.
Find out what can cause tennis elbow, how to treat it and if there is anything that you can do to stop it from happening.
Find out about lumps and swellings in the testicles, including what can cause them and when to get medical advice.
Read about thalassaemia, a group of blood disorders that affect a substance called haemoglobin. Find out about the symptoms, causes and treatments.
Read about threadworms (pinworms), which are tiny worms in your poo. They're common in children and spread easily. You can treat them without seeing a GP.
Find out about tick-borne encephalitis (TBE), a viral infection spread to humans by the bite of a small spider-like parasite called a tick.
Tics are unintentional, fast and repetitive muscle movements. Find out how long they last, when to get medical advice and how they can be treated.
Find out about tinnitus (hearing ringing or buzzing), including what you can do to help you cope with it and when to get medical help.
Find out about tonsillitis, which is when the tonsils at the sides of your throat become swollen due to a viral or bacterial infection. Find out about causes and treatments.
Find out about Tourette's syndrome, a condition that causes a person to make involuntary sounds and movements called tics. Read about the symptoms and causes, plus find out how it's diagnosed and treated.
Find out about toxocariasis, including how you get it, whether it’s serious, when to get medical help and how to reduce your risk of getting it.
Read about toxoplasmosis, a parasite infection that can be dangerous, especially for pregnant women and people with a weakened immune system.
NHS information about a tracheostomy, including what it is, when it's used, how it's carried out, and the possible risks and complications.
Find out about transient ischaemic attack (TIA) or "mini stroke", including what causes it, the symptoms, how it's diagnosed, and when to seek medical advice.
Read about transurethral resection of the prostate (TURP), a surgical procedure used to cut away a section of the prostate gland if it's causing problems with peeing.
Read about trichomoniasis, a sexually transmitted infection (STI) caused by a parasite called Trichomonas vaginalis (TV).
Find out about trigeminal neuralgia, which is sudden, severe facial pain, often described as sharp, shooting or like an electric shock.
Trigger finger is a condition that affects 1 or more of the hand's tendons, making it difficult to bend the affected finger or thumb.
NHS information about tuberculosis (TB), including symptoms, when to get medical help, treatments and causes.
Tuberous sclerosis, also known as tuberous sclerosis complex, is a rare genetic condition that causes mainly non-cancerous (benign) tumours to develop in different parts of the body.
Turner syndrome is a genetic disorder that only affects females. It causes a wide range of symptoms and some distinctive characteristics.
Read about type 2 diabetes, a condition that causes a person's blood sugar level to become too high.
Find out about typhoid fever, what causes it, how it's treated and what you can do to protect yourself if you're travelling to a high-risk area.
Read about having a tremor, which is when you're not able to control shaking or trembling in part of your body, or shaking hands.
Find out about temporal arteritis (giant cell arteritis), a condition when arteries become inflamed. It's a serious condition that needs urgent treatment.
Find out more about thrush (yeast infection), including what the symptoms are, how it's treated, why it happens and how to help prevent it.
NHS information about common causes of twitches in your eyes or muscles and advice about what to do.
Find out about causes of pain in testicles (balls) and when and where to get medical help.
Find out about some of the common causes of tiredness and fatigue, treatments and things you can do to help, plus when to get medical advice.
Find out what you can do to ease toe pain, what could be causing the pain and when to get medical help.
Find out about teeth whitening including who can perform it, what the procedure involves and what the risks are.
Find out more about what to do about thumb pain, when to get help and the common causes.
NHS guide to type 1 diabetes.
Find out about thyroid cancer, including what the symptoms are, what to do if you think you have it, how it's treated and where to get support.
Find out about thoracic outlet syndrome, where nerves or blood vessels near the top of the ribs get squashed. It's often linked to having an extra rib (cervical rib).
Find out about testicular cancer, including what the symptoms are, what to do if you think you have it, how it's treated and where to get support.
Trichotillomania is when someone cannot resist the urge to pull out their hair.
Get advice about getting vaccinated before travelling abroad and information about common travel vaccines.
Find out about the Td/IPV vaccine (3-in-1 teenage booster) for tetanus, diphtheria and polio, including who it's for, how to get it and possible side effects.