Explore popular diseases in clinical trials

Check which popular diseases are currently being frequently studied.

See also our rare diseases glossary and drug database.

Starting by letter

To open the diseases glossary, select a letter from the list below.

Most popular diseases

The list below features the most popular diseases currently involved in ongoing clinical trials.

Disease trials
Non-small cell lung cancer 228
Breast cancer 94
Obesity 86
Prostate cancer 73
Colorectal cancer 69
Ovarian cancer 66
Non-small cell lung cancer metastatic 66
Crohn’s disease 61
Type 2 diabetes mellitus 54
Rheumatoid arthritis 54
Triple negative breast cancer 52
Hormone receptor positive HER2 negative breast cancer 52
Asthma 51
Acute myeloid leukaemia 50
Squamous cell carcinoma of head and neck 50
Chronic kidney disease 49
Neoplasm 48
Colorectal cancer metastatic 47
Hepatocellular carcinoma 47
Systemic lupus erythematosus 40
Colitis ulcerative 40
Multiple sclerosis 39
Overweight 39
Dementia Alzheimer’s type 39
Gastric cancer 38
Myelodysplastic syndrome 37
Parkinson’s disease 37
HER2 positive breast cancer 37
Glioblastoma 37
Atrial fibrillation 34
Bladder cancer 34
Chronic obstructive pulmonary disease 33
Ischaemic stroke 33
Prostate cancer metastatic 33
Myasthenia gravis 32
Renal transplant 31
Type 1 diabetes mellitus 31
Head and neck cancer 31
Endometrial cancer 31
Malignant melanoma 31
Non-small cell lung cancer stage IV 31
Diffuse large B-cell lymphoma 31
Breast cancer metastatic 31
HIV infection 30
Dermatitis atopic 28
Cholangiocarcinoma 28
Coronary artery disease 28
Plasma cell myeloma 28
Pulmonary arterial hypertension 28
Neoplasm malignant 27
Rectal cancer 27
Renal cell carcinoma 26
Pancreatic carcinoma 26
Schizophrenia 26
Duchenne muscular dystrophy 25
Non-small cell lung cancer stage III 25
Follicular lymphoma 25
COVID-19 25
Migraine 24
Hormone receptor positive breast cancer 24
Idiopathic pulmonary fibrosis 24
Non-small cell lung cancer stage IIIB 24
Sepsis 24
Chronic lymphocytic leukaemia 24
Soft tissue sarcoma 24
Mantle cell lymphoma 23
Small cell lung cancer extensive stage 23
Colon cancer 23
Fallopian tube cancer 23
Influenza 22
Small cell lung cancer 21
Interstitial lung disease 21
Acute myocardial infarction 21
Oesophageal adenocarcinoma 21
Amyotrophic lateral sclerosis 21
Chronic rhinosinusitis with nasal polyps 20
Cystic fibrosis 20
Glioma 20
Myelofibrosis 19
Neuroblastoma 19
B-cell lymphoma 19
Sickle cell disease 19
Major depression 19
Procedural pain 19
Axial spondyloarthritis 18
Osteoarthritis 18
Breast cancer female 17
Critical illness 17
Acute kidney injury 17
Hereditary angioedema 17
Relapsing-remitting multiple sclerosis 16
Acute coronary syndrome 16
IgA nephropathy 16
Psoriasis 16
Gastrooesophageal cancer 16
Ewing’s sarcoma 16
Cardiac failure 16
Vitiligo 16
Transitional cell carcinoma 15
Giant cell arteritis 15

Diseases starting with t

  • 4

    T-cell lymphoma

    T-cell lymphoma is a rare form of cancer that develops when T-cells, a type of white blood cell that fights infection, grow out of control. This disease makes up only about 7% to 15% of all non-Hodgkin lymphomas and includes many different subtypes, each with distinct characteristics and treatment approaches.

  • 0

    T-cell type acute leukaemia

    T-cell type acute leukaemia is an aggressive blood cancer affecting the bone marrow, where immature and abnormal T-cells accumulate and crowd out healthy blood cells needed to fight infection and maintain health.

  • 0

    Tachypnoea

    Tachypnea is rapid, shallow breathing that occurs when your body takes in too many breaths per minute. While it can be normal during exercise, it can also signal serious health problems when it happens at rest, affecting everyone from newborns to adults.

  • 1

    Takayasu’s arteritis

    Takayasu’s arteritis is a rare inflammatory disease that attacks the body’s largest arteries, causing them to narrow, weaken, or develop dangerous bulges. This condition mainly affects young women, particularly those of Asian descent, and can lead to serious complications including stroke and heart failure if left untreated.

  • 3

    Tardive dyskinesia

    Tardive dyskinesia is a movement disorder that causes involuntary, repetitive body movements you cannot control. It typically develops as a side effect of medications that block dopamine in your brain, and while symptoms can range from barely noticeable to severe, understanding this condition is the first step toward managing it effectively.

  • 0

    Temporomandibular pain and dysfunction syndrome

    Temporomandibular pain and dysfunction syndrome affects the jaw joints and surrounding muscles, causing pain, clicking sounds, and difficulty moving the jaw. This common condition impacts millions of adults, particularly women, but most cases improve with conservative treatment and self-care measures.

  • 1

    Tendon disorder

    Tendon disorders affect the flexible bands of tissue that connect your muscles to bones, causing pain and limiting movement. While often called tendonitis, these conditions usually involve tissue breakdown rather than inflammation, and they require rest, proper care, and time to heal.

  • 1

    Tendon injury

    Tendon injuries are a widespread problem that can affect anyone, from athletes to office workers, impacting the tough fibers connecting muscles to bones and causing pain that can last for months if not properly managed.

  • 0

    Tendon rupture

    A tendon rupture is a serious injury where the thick tissue connecting muscle to bone tears completely or partially, causing severe pain and loss of function that can take months to heal.

  • 1

    Tertiary adrenal insufficiency

    Tertiary adrenal insufficiency is a condition where the brain’s control center for hormone production stops sending the right signals to the adrenal glands, resulting in dangerously low levels of cortisol, a hormone essential for life.

  • 0

    Testicular germ cell cancer

    Testicular germ cell cancer is a highly treatable form of cancer that primarily affects young men, with most cases occurring between ages 15 and 35. Understanding this disease, its warning signs, and treatment options can make a crucial difference in outcomes.

  • 0

    Testicular germ cell tumour

    Testicular germ cell tumours are the most common cancers affecting young men, but they are also among the most curable. Understanding this disease can help patients and families navigate diagnosis, treatment, and the path to recovery.

  • 1

    Testicular leiomyosarcoma

    Testicular leiomyosarcoma is an extremely rare cancer that develops from smooth muscle cells in or around the testicle, affecting primarily middle-aged and older men, though cases in younger individuals have been documented without any known risk factors.

  • 1

    Testicular seminoma (pure) stage I

    Stage I testicular seminoma is the earliest and most treatable form of this cancer, with cure rates approaching 100% when caught early and managed appropriately.

  • 1

    Testicular seminoma (pure) stage II

    Stage II seminoma is a highly curable form of testicular cancer where the disease has spread to nearby lymph nodes, but treatment outcomes remain excellent with proper care and management.

  • 0

    Testis cancer

    Testicular cancer is a growth of cells that develops in the testicles, most commonly affecting men between the ages of 15 and 45. While it’s not a common type of cancer, it’s highly treatable with cure rates exceeding 90%, making it one of the most curable cancers when diagnosed and treated promptly.

  • 0

    Testosterone deficiency syndrome

    Testosterone deficiency syndrome is a condition that occurs when the body does not produce enough testosterone, the main male hormone that plays a key role in sex drive, muscle mass, and physical and mental energy.

  • 0

    Tetanus

    Tetanus is a serious bacterial infection that attacks the nervous system, causing painful muscle spasms throughout the body. While it can be life-threatening, vaccination offers highly effective protection, making this once-common disease now rare in countries with strong immunization programs.

  • 4

    Thalassaemia

    Thalassaemia is an inherited blood disorder that disrupts the body’s ability to produce healthy haemoglobin, causing red blood cells to form incorrectly and leading to anemia that ranges from mild to life-threatening.

  • 0

    Thalassaemia alpha

    Alpha thalassemia is an inherited blood disorder that reduces the body’s ability to produce hemoglobin, the protein in red blood cells that carries oxygen throughout the body. The severity can range from having no symptoms at all to life-threatening complications before or shortly after birth.

  • 2

    Thalassaemia beta

    Beta thalassaemia is an inherited blood disorder that affects the body’s ability to make hemoglobin, the iron-rich protein that enables red blood cells to carry oxygen throughout the body. This condition can range from mild forms that cause no symptoms to severe forms requiring lifelong treatment with regular blood transfusions.

  • 5

    Thermal burn

    Thermal burns are skin injuries caused by excessive heat from contact with hot surfaces, liquids, steam, or flames, affecting approximately 450,000 people annually in the United States, with most burns being minor enough to treat at home.

  • 3

    Thrombectomy

    A thrombectomy is a surgical procedure that removes blood clots from blood vessels, restoring blood flow to vital organs and potentially preventing death or serious disability when performed promptly.

  • 1

    Thromboangiitis obliterans

    Thromboangiitis obliterans is a rare disease that causes blood vessels in the arms and legs to become inflamed and blocked, leading to severe pain and tissue damage. Almost everyone who develops this condition uses tobacco, and quitting all tobacco use is the only proven way to stop the disease from getting worse.

  • 4

    Thrombocytopenia

    Thrombocytopenia is a condition where your blood has too few platelets, the tiny cells that help stop bleeding by forming clots. When platelet levels drop too low, you may bleed longer than usual from small cuts, bruise more easily, or even experience serious internal bleeding. Understanding this condition can help you manage it safely and maintain a good quality of life.

  • 0

    Thrombocytosis

    Thrombocytosis is a condition where your body has too many platelets in the blood. While many people have no symptoms and may not need treatment, understanding this condition is important because it can sometimes increase the risk of blood clots or, less commonly, bleeding problems.

  • 0

    Thromboembolectomy

    Thromboembolectomy is a surgical procedure designed to remove blood clots from blood vessels, potentially saving lives by restoring normal blood flow and preventing serious complications such as stroke, heart attack, or limb loss.

  • 1

    Thrombolysis

    Thrombolysis is a life-saving treatment that dissolves dangerous blood clots blocking your blood vessels. Time is critical—when you’re having a heart attack or stroke, every minute counts, and this therapy can mean the difference between recovery and permanent damage.

  • 2

    Thrombosis

    Thrombosis is a serious medical condition where blood clots form inside your blood vessels or heart, blocking normal blood flow and potentially causing life-threatening emergencies like stroke, heart attack, or pulmonary embolism.

  • 4

    Thrombosis prophylaxis

    Preventing blood clots before they form is one of the most important safety measures in hospitals today, yet only about half of at-risk patients receive the protective treatments they need. Understanding who needs protection and what methods work best can save lives and prevent serious complications.

  • 4

    Thrombotic microangiopathy

    Thrombotic microangiopathy is a rare but life-threatening group of blood disorders where tiny blood clots form in the smallest blood vessels throughout the body, leading to organ damage and requiring urgent medical care.

  • 3

    Thrombotic thrombocytopenic purpura

    Thrombotic thrombocytopenic purpura is a rare blood disorder that causes dangerous blood clots to form throughout the body, blocking blood flow to vital organs like the brain, kidneys, and heart. Without urgent treatment, this condition can be life-threatening, but with proper care, most people can recover and manage their health.

  • 2

    Thymic carcinoma

    Thymic carcinoma is a rare and aggressive form of cancer that develops in the thymus, a small gland located behind the breastbone that helps your body fight infections. Unlike its less aggressive counterpart thymoma, thymic carcinoma grows quickly and is more likely to spread to other parts of the body, making it more challenging to treat.

  • 2

    Thymoma

    Thymomas are rare cancers that develop in a small gland behind your breastbone called the thymus. While they often grow slowly and rarely spread, these tumors can cause serious symptoms and may be linked to conditions where your immune system attacks your own body.

  • 1

    Thymoma malignant

    Malignant thymoma is a rare cancer that grows in the thymus, a small gland located in your chest behind your breastbone. While it most often does not cause symptoms in the early stages, it has the ability to spread and invade nearby tissues, making early detection and treatment crucial.

  • 7

    Thyroid cancer

    Thyroid cancer develops in a small butterfly-shaped gland at the base of your neck that controls vital body functions like heart rate, metabolism, and body temperature. While it is less common than many other cancers, its diagnosis has been rising worldwide, largely due to better detection methods. The good news is that most thyroid cancers are highly treatable, with excellent survival rates when caught early.

  • 1

    Thyroid cancer metastatic

    Metastatic thyroid cancer occurs when cancer cells spread from the thyroid gland to other parts of the body. While most thyroid cancers have an excellent outlook, understanding what happens when the disease spreads and the available treatment options is essential for patients facing this diagnosis.

  • 0

    Thyroid disorder

    Thyroid disorder is an umbrella term for conditions that prevent your thyroid from producing the right amount of hormones. These disorders affect millions of people, particularly women, and can cause symptoms ranging from fatigue and weight changes to mood problems and irregular heartbeat.

  • 0

    Thyroid mass

    A thyroid mass is an abnormal growth or lump that forms in the thyroid gland, the small butterfly-shaped organ at the base of your neck. While these masses are very common—affecting up to 60% of adults—most are not cancerous and don’t cause symptoms, though proper evaluation is important to rule out serious conditions.

  • 2

    Thyroidectomy

    Thyroidectomy is a surgical procedure to remove all or part of the thyroid gland, a butterfly-shaped organ in your neck that controls your metabolism. This operation may be necessary for conditions like thyroid cancer, large goiters that make breathing or swallowing difficult, or an overactive thyroid that doesn’t respond to other treatments.

  • 1

    Tinnitus

    Tinnitus is when you hear sounds inside your head that no one else can hear—like ringing, buzzing, or humming. This common problem affects millions of people worldwide and can range from a minor annoyance to a condition that seriously impacts daily life.

  • 1

    Tissue anoxia

    Tissue anoxia is a life-threatening condition where organs and tissues are completely deprived of oxygen, potentially causing permanent damage within minutes if not treated immediately.

  • 1

    Tongue neoplasm malignant stage unspecified

    Tongue cancer occurs when cells on the tongue grow and divide uncontrollably, forming a tumor that can affect your ability to speak, eat, and swallow.

  • 3

    Tonsillitis

    Tonsillitis is a common condition that causes swelling and infection of the tonsils, the two oval-shaped pads of tissue at the back of your throat. While it can affect people of all ages, it is most common in children and teenagers, and most people will experience it at least once in their lifetime.

  • 0

    Tooth loss

    Tooth loss in adults is more than just a cosmetic concern—it’s a warning sign that something deeper is happening with your oral health. While losing baby teeth is a normal childhood milestone, losing permanent teeth can trigger a cascade of problems affecting your ability to eat, speak, and feel confident in your smile.

  • 1

    Torticollis

    Torticollis, also known as wryneck or twisted neck, is a condition where the head tilts to one side, making it difficult to move the neck normally. While this condition can affect anyone from newborns to adults, early recognition and treatment can lead to excellent outcomes for most people.

  • 2

    Tourette’s disorder

    Tourette’s disorder is a neurological condition that causes sudden, repeated movements or sounds called tics that a person cannot control. While the symptoms can range from mild to severe, most people experience significant improvement as they grow older, and many find that tics lessen or disappear by early adulthood.

  • 1

    Toxic epidermal necrolysis

    Toxic epidermal necrolysis is a rare but extremely serious skin condition that causes large areas of skin to blister and peel away, leaving raw, painful wounds that resemble severe burns. This life-threatening reaction is usually triggered by certain medications and affects at least 30% of the body’s surface, including sensitive areas like the mouth, eyes, and genitals.

  • 0

    Toxic nodular goitre

    Toxic nodular goitre is a condition where one or more growths in your thyroid gland start producing too much thyroid hormone on their own, leading to an overactive thyroid that can affect your heart, bones, and overall wellbeing.

  • 0

    Toxicity to various agents

    Exposure to harmful chemicals and toxic substances can occur every day through what we eat, breathe, touch, or swallow, affecting our health in ways that range from mild symptoms to life-threatening conditions.

  • 1

    Transferrin decreased

    Decreased transferrin levels in your blood can signal important health conditions. This protein, produced by your liver, plays a crucial role in transporting iron throughout your body, and when levels drop, it may indicate problems ranging from liver disease to chronic inflammation.

  • 4

    Transient ischaemic attack

    A transient ischaemic attack is a temporary disruption of blood flow to the brain that causes stroke-like symptoms lasting from a few minutes to hours. While the effects resolve without lasting damage, a TIA serves as a critical warning sign that a full stroke may follow, making immediate medical attention essential even after symptoms disappear.

  • 0

    Transitional cell cancer of renal pelvis and ureter metastatic

    Transitional cell cancer of the renal pelvis and ureter that has spread to other parts of the body is an advanced form of this rare cancer. While early-stage disease is highly treatable, metastatic cancer poses greater challenges. Understanding this advanced condition helps patients and families navigate treatment options and make informed decisions about care.

  • 1

    Transitional cell cancer of the renal pelvis and ureter

    Transitional cell cancer of the renal pelvis and ureter is a rare cancer affecting the upper urinary tract, most commonly diagnosed in adults over age 65. When caught early, it is highly treatable, though it often recurs and requires careful long-term monitoring.

  • 14

    Transitional cell carcinoma

    Transitional cell carcinoma is a type of cancer that develops in the cells lining your urinary system, including the bladder, kidneys, and the tubes connecting them. Accounting for about 90% of bladder cancers, it can be highly treatable when detected early, though it frequently returns after treatment.

  • 1

    Transitional cell carcinoma metastatic

    Transitional cell carcinoma metastatic is an advanced stage of cancer that has spread from its original location in the urinary tract to other parts of the body, requiring specialized treatment approaches focused on prolonging survival and maintaining quality of life.

  • 0

    Transitional cell carcinoma recurrent

    When transitional cell carcinoma returns after treatment, it presents unique challenges that require ongoing monitoring and specialized care.

  • 0

    Transitional cell carcinoma urethra

    Transitional cell carcinoma of the urethra is a rare cancer that develops in the cells lining the urethra, the tube through which urine exits the body. While uncommon, this cancer requires careful attention as it can spread to nearby tissues and lymph nodes.

  • 2

    Transplant rejection

    Transplant rejection occurs when the body’s immune system attacks a newly transplanted organ or tissue, recognizing it as foreign. While this complication can be serious, early detection and proper treatment with medications can often reverse rejection and protect the transplanted organ.

  • 0

    Transplantation complication

    While organ transplantation offers life-saving treatment for people with failing organs, it comes with significant challenges that require careful management and lifelong attention.