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 240
Breast cancer 99
Obesity 92
Prostate cancer 77
Colorectal cancer 69
Ovarian cancer 68
Crohn’s disease 67
Non-small cell lung cancer metastatic 64
Rheumatoid arthritis 55
Squamous cell carcinoma of head and neck 54
Triple negative breast cancer 54
Chronic kidney disease 50
Asthma 50
Hepatocellular carcinoma 47
Neoplasm 47
Acute myeloid leukaemia 47
Colorectal cancer metastatic 46
Overweight 45
Multiple sclerosis 43
Colitis ulcerative 40
Parkinson’s disease 40
HER2 positive breast cancer 39
Gastric cancer 38
Myelodysplastic syndrome 38
Dementia Alzheimer’s type 37
Glioblastoma 36
Bladder cancer 34
Atrial fibrillation 34
Prostate cancer metastatic 34
Renal transplant 33
Ischaemic stroke 33
Diffuse large B-cell lymphoma 32
Chronic obstructive pulmonary disease 32
Head and neck cancer 32
Non-small cell lung cancer stage IV 31
Breast cancer metastatic 30
Coronary artery disease 29
Myasthenia gravis 29
Malignant melanoma 29
Endometrial cancer 28
Cholangiocarcinoma 28
Rectal cancer 27
Pulmonary arterial hypertension 27
Dermatitis atopic 27
Idiopathic pulmonary fibrosis 27
Soft tissue sarcoma 26
Non-small cell lung cancer stage III 26
Plasma cell myeloma 25
Pancreatic carcinoma 25
Small cell lung cancer extensive stage 25
Sepsis 25
Renal cell carcinoma 25
Schizophrenia 24
COVID-19 24
Duchenne muscular dystrophy 24
Non-small cell lung cancer stage IIIB 24
Follicular lymphoma 24
Hormone receptor positive breast cancer 24
Fallopian tube cancer 23
Amyotrophic lateral sclerosis 23
Mantle cell lymphoma 23
Influenza 22
Neoplasm malignant 22
Chronic lymphocytic leukaemia 21
Acute myocardial infarction 21
Major depression 21
Small cell lung cancer 21
Sickle cell disease 21
Interstitial lung disease 21
Cystic fibrosis 21
Breast cancer female 20
Osteoarthritis 20
Glioma 20
Neuroblastoma 20
Chronic rhinosinusitis with nasal polyps 20
Oesophageal adenocarcinoma 20
Myelofibrosis 19
B-cell lymphoma 19
Critical illness 18
Procedural pain 18
Acute kidney injury 18
Psoriasis 18
Axial spondyloarthritis 18
Acute coronary syndrome 17
Vitiligo 17
Hereditary angioedema 17
Relapsing-remitting multiple sclerosis 17
Ewing’s sarcoma 17
IgA nephropathy 17
Gastrooesophageal cancer 16
Juvenile idiopathic arthritis 16
Cardiac failure 16
Uveal melanoma 16
Chronic hepatitis B 16
Allogenic stem cell transplantation 15
Giant cell arteritis 15
Chronic spontaneous urticaria 15
Cardiac arrest 15
Septic shock 14
Malignant melanoma stage III 14

All diseases

  • 6

    Pulmonary fibrosis

    Pulmonary fibrosis is a lung disease where tissue becomes scarred and thickened, making breathing progressively more difficult. While the exact cause is often unknown, understanding this condition and its management can help improve quality of life for those affected.

  • 10

    Pulmonary hypertension

    Pulmonary hypertension is a serious condition where blood pressure becomes dangerously high in the arteries between your heart and lungs, making it harder for blood to flow and forcing your heart to work much harder than normal.

  • 1

    Pulmonary resection

    Pulmonary resection is a major surgical procedure to remove part or all of a damaged or diseased lung. While it represents a serious operation, people can live with only one lung or with part of a lung removed, making this an important treatment option for various lung conditions.

  • 4

    Pulmonary sarcoidosis

    Pulmonary sarcoidosis is a condition where the immune system overreacts and forms tiny lumps of inflamed cells called granulomas in the lungs, affecting how well you can breathe and causing symptoms that range from mild to severe.

  • 3

    Pulmonary tuberculosis

    Pulmonary tuberculosis is a serious bacterial infection that mainly affects the lungs but can spread to other parts of the body. While highly contagious, it is both preventable and curable with proper treatment using antibiotics, though the infection requires long-term medication lasting several months.

  • 0

    Pulmonary vascular disorder

    Pulmonary vascular disorder is a broad term for any condition that affects the blood vessels between your heart and lungs, causing symptoms like shortness of breath and potentially leading to serious heart problems if left untreated.

  • 1

    Pulmonary venous thrombosis

    Pulmonary venous thrombosis is a rare but potentially life-threatening condition where blood clots form in the veins that carry oxygen-rich blood from the lungs to the heart. Unlike the more common blood clots in the legs, this condition often goes unnoticed until serious complications occur.

  • 1

    Pustular psoriasis

    Pustular psoriasis is a rare and serious form of psoriasis that causes painful, pus-filled blisters to appear on inflamed skin. While it affects only about 3% of people with psoriasis, this condition requires prompt medical attention, especially when it spreads quickly across large areas of the body.

  • 2

    Pyelonephritis

    Pyelonephritis is a bacterial infection of the kidneys that can cause serious health problems if not treated quickly. While most cases begin as bladder infections that spread upward, prompt treatment with antibiotics can prevent lasting kidney damage and life-threatening complications.

  • 3

    Pyelonephritis acute

    Acute pyelonephritis is a bacterial infection of the kidneys that can cause sudden and severe symptoms, including fever, flank pain, and nausea. While most cases can be treated successfully with antibiotics, prompt medical attention is essential to prevent serious complications.

  • 1

    Pyoderma

    Pyoderma gangrenosum is a rare and painful skin condition that causes large, open sores called ulcers. Despite its name, this condition is not an infection and is not contagious. It often begins as a small bump or blister that rapidly grows into a deep wound, requiring prompt medical attention to prevent complications.

  • 2

    Pyoderma gangrenosum

    Pyoderma gangrenosum is a rare and painful skin condition where small bumps or blisters rapidly turn into large, open sores that can be difficult to diagnose and treat, often affecting people with other health conditions like inflammatory bowel disease or arthritis.

  • 0

    Pyogenic sterile arthritis pyoderma gangrenosum and acne syndrome

    PAPA syndrome is a rare genetic condition that causes recurring joint inflammation, severe skin ulcers, and acne. It typically begins with joint problems in early childhood and develops skin symptoms during the teenage years.

  • 1

    Pyrexia

    Pyrexia, commonly known as fever, is your body’s natural way of fighting infection. When your temperature rises above normal, it signals that your immune system is working hard to combat invaders like viruses or bacteria. While uncomfortable, this protective response plays a crucial role in helping you recover from illness.

  • 4

    Pyruvate kinase deficiency anaemia

    Pyruvate kinase deficiency anaemia is a rare inherited blood disorder where red blood cells break down too quickly, causing a shortage of healthy cells to carry oxygen throughout the body. The condition affects people from birth, but symptoms can range from severe and life-threatening in newborns to so mild that they go unnoticed until adulthood.

  • 5

    Rabies

    Rabies is a deadly viral disease that attacks the brain and nervous system, but it can be completely prevented if you get medical treatment quickly after being bitten or scratched by an infected animal.

  • 0

    Radiation skin injury

    Radiation skin injury affects the vast majority of people who receive radiation therapy for cancer, with nearly 90% experiencing moderate to severe skin reactions that can significantly impact their quality of life and treatment journey.

  • 0

    Radicular pain

    Radicular pain is a condition where pain radiates along a nerve pathway from the spine to other parts of the body, caused by compression or irritation of nerve roots where they exit the spinal column.

  • 1

    Radiologically isolated syndrome

    Radiologically Isolated Syndrome (RIS) occurs when brain or spinal cord scans reveal abnormalities characteristic of multiple sclerosis, yet the person experiences no neurological symptoms. This unexpected discovery creates both uncertainty and opportunity for early monitoring and possible intervention.

  • 4

    Radius fracture

    A radius fracture is one of the most common breaks in the arm, particularly near the wrist. This injury can happen to anyone—from children falling on the playground to older adults experiencing a simple stumble. Understanding what happens when your radius breaks and how it heals can help you navigate the recovery process more confidently.

  • 0

    Rapid eye movement sleep behaviour disorder

    Rapid eye movement sleep behaviour disorder is a condition in which people physically act out their dreams while asleep, sometimes with violent movements that can cause injury to themselves or their sleeping partners.

  • 1

    Rasmussen encephalitis

    Rasmussen encephalitis is a very rare brain condition that causes ongoing inflammation affecting one side of the brain, leading to frequent seizures that are difficult to control with medicine, progressive weakness on one side of the body, and mental decline.

  • 1

    Raynaud’s phenomenon

    When your fingers or toes suddenly turn white or blue in response to cold or stress, you may be experiencing a condition that affects your blood vessels and circulation, causing temporary but sometimes painful episodes that can be managed with the right approach.

  • 2

    Rectal adenocarcinoma

    Rectal adenocarcinoma is a type of cancer that forms in the tissues of the rectum, typically starting as abnormal growths called polyps that develop over many years before becoming cancerous tumors.

  • 27

    Rectal cancer

    Rectal cancer is a type of cancer that develops in the last several inches of the large intestine, known as the rectum. While it shares similarities with colon cancer, rectal cancer requires different treatment approaches due to the rectum’s location deep within the pelvis, close to other vital organs.

  • 1

    Rectal cancer recurrent

    Recurrent rectal cancer occurs when cancer returns after initial treatment, affecting 6 to 12 percent of patients who previously underwent surgery with or without chemotherapy and radiation therapy. Understanding this complex condition and its management options is essential for patients facing this challenge.

  • 3

    Rectal cancer stage II

    Stage II rectal cancer means the cancer has grown into or through the outer layers of the rectum wall, but it has not yet spread to nearby lymph nodes or distant parts of the body. Understanding your stage helps your healthcare team plan the most effective treatment approach.

  • 3

    Rectal cancer stage III

    Stage III rectal cancer means the disease has spread to nearby lymph nodes but has not yet reached distant parts of the body. Understanding this stage and the available treatment options is an important step in facing this diagnosis.

  • 0

    Rectal neoplasm

    Rectal neoplasm, commonly known as rectal cancer, is a disease where abnormal cells grow in the tissues of the rectum, the last several inches of the large intestine. While it typically develops slowly over many years, early detection through screening can catch growths before they become cancerous, and surgery may cure the disease when found early.

  • 0

    Rectosigmoid cancer

    Rectosigmoid cancer is a type of cancer that forms in the area where the colon meets the rectum, presenting unique challenges in treatment decisions that depend on the tumor’s exact location.

  • 0

    Red blood cell abnormality

    Red blood cell disorders affect millions of people worldwide, disrupting how oxygen reaches every part of the body and potentially causing serious health complications that require lifelong management.

  • 12

    Relapsing multiple sclerosis

    Relapsing multiple sclerosis is the most common form of a chronic disease affecting the central nervous system, where symptoms flare up during attacks followed by periods of partial or complete recovery. Understanding this condition and how to manage it can help you maintain quality of life and slow disease progression.

  • 16

    Relapsing-remitting multiple sclerosis

    Relapsing-remitting multiple sclerosis is the most common form of multiple sclerosis, affecting about 80% to 85% of people diagnosed with MS. This type of MS follows a pattern of symptom flare-ups followed by periods of partial or complete recovery, making it distinct from other forms of the disease.

  • 4

    Renal cancer

    Renal cancer, also known as kidney cancer, is a disease where cells in the kidney grow abnormally and out of control, forming tumors. It is one of the ten most common cancers in adults, with the majority of cases being renal cell carcinoma. While early stages often have no symptoms, advances in imaging and treatment have made kidney cancer more treatable than ever before.

  • 1

    Renal cancer metastatic

    Metastatic renal cell carcinoma is kidney cancer that has spread beyond the kidneys to other parts of the body, most commonly to the lungs, bones, brain, or liver. Though it cannot usually be cured, many treatments can help control the disease and manage symptoms, allowing patients to maintain quality of life.

  • 0

    Renal cancer recurrent

    Kidney cancer can return even years after successful surgery, affecting about 1 in 5 people who undergo treatment for localized disease. Understanding the risk factors, warning signs, and available treatments helps patients navigate this challenging possibility with their medical team.

  • 1

    Renal cancer stage IV

    Stage 4 kidney cancer is the most advanced form of the disease, where cancer that started in the kidney has spread beyond the organ to other parts of the body. While this diagnosis is serious, treatments are available that can often control the cancer and help relieve symptoms.

  • 25

    Renal cell carcinoma

    Renal cell carcinoma is the most common type of kidney cancer in adults, accounting for up to 85% of all kidney cancers. Often it causes no symptoms in early stages, making it difficult to detect until it grows larger or spreads to other parts of the body.

  • 1

    Renal cell carcinoma stage IV

    Stage 4 renal cell carcinoma is the most advanced form of kidney cancer, where cancer has spread beyond the kidney to other parts of the body. Although this stage is challenging, treatment options including targeted therapy, immunotherapy, and surgery can help control the disease and manage symptoms.

  • 1

    Renal disorder

    Renal disorders affect millions of people worldwide, often developing silently over time, but with proper care and early detection, many individuals can manage these conditions and maintain a good quality of life.

  • 6

    Renal failure

    When your kidneys lose the ability to filter waste from your blood, dangerous levels of fluid and toxins can build up in your body. Understanding this serious condition and the available treatments can help you take charge of your health and maintain a good quality of life.

  • 4

    Renal impairment

    Renal impairment is a condition where the kidneys lose their ability to filter blood properly, affecting millions of people worldwide and potentially leading to serious health complications if left untreated.

  • 1

    Renal injury

    Renal injury, also called acute kidney injury, is when your kidneys suddenly stop working properly. It can happen over hours or days, and while it can be mild, it may also become severe enough to require immediate medical attention. The good news is that many people recover kidney function with quick treatment.

  • 32

    Renal transplant

    A renal transplant, also known as a kidney transplant, is a surgical procedure to place a healthy kidney from a donor into a person whose kidneys no longer work properly. This treatment offers improved survival and quality of life compared to dialysis for people with kidney failure.

  • 2

    Reperfusion injury

    Reperfusion injury is a paradoxical medical problem where restoring blood flow to oxygen-starved tissues can actually worsen the damage already caused by lack of blood supply. This seemingly contradictory process affects multiple organs and can turn a medical emergency into an even more serious health crisis.

  • 1

    Respiratory distress

    Respiratory distress is a serious breathing problem that can affect people of all ages, from premature newborns to critically ill adults, and requires immediate medical attention to prevent life-threatening complications.

  • 2

    Respiratory failure

    Respiratory failure is a serious medical condition that occurs when your body cannot get enough oxygen into your blood or cannot remove enough carbon dioxide from it. This condition can develop suddenly or gradually over time, and while acute respiratory failure is life-threatening and requires immediate emergency care, chronic respiratory failure can often be managed at home with proper treatment and support.

  • 2

    Respiratory syncytial virus bronchiolitis

    Respiratory syncytial virus bronchiolitis is a viral infection that affects the smallest airways in the lungs of infants and young children, often turning what seems like a simple cold into a serious breathing problem requiring urgent medical attention.

  • 11

    Respiratory syncytial virus infection

    Respiratory syncytial virus (RSV) is a common virus that nearly all children catch before they turn two years old, yet it remains one of the most serious respiratory infections for babies, older adults, and people with certain health conditions.

  • 2

    Respiratory tract infection

    Respiratory tract infections are among the most common illnesses affecting millions of people each year, ranging from mild colds to serious lung infections that require medical attention.

  • 2

    Respiratory tract infection viral

    Viral respiratory infections are among the most common illnesses worldwide, affecting millions of people each year and leading to thousands of hospitalizations. These infections impact the parts of your body involved in breathing and can range from mild colds to more serious conditions requiring medical care.

  • 3

    Restless legs syndrome

    Restless legs syndrome is a condition that creates an overwhelming urge to move your legs, especially when trying to rest or sleep. Between 7% and 10% of people in the United States experience this condition, which can disrupt sleep and affect daily life.

  • 0

    Retinal artery occlusion

    Retinal artery occlusion is an eye emergency that occurs when blood flow to the retina is suddenly blocked, often leading to severe and painless vision loss in one eye within minutes or hours.

  • 0

    Retinal neovascularisation

    Retinal neovascularisation involves the abnormal growth of new blood vessels in the retina—a process that attempts to help the eye but often causes serious harm. These fragile vessels can leak blood and fluid, threatening your vision if not detected and treated early.

  • 2

    Retinal vein occlusion

    Retinal vein occlusion is a blockage in a small blood vessel that carries blood away from the back of your eye. This condition can cause sudden vision changes and, without proper treatment, may lead to serious complications that affect your sight.

  • 9

    Retinitis pigmentosa

    Retinitis pigmentosa is a group of inherited eye diseases that cause cells in the retina to gradually break down, leading to progressive vision loss that typically begins in childhood with difficulty seeing at night and eventually narrows the field of vision.

  • 2

    Retinoblastoma

    Retinoblastoma is a rare eye cancer that develops in the retina, the light-sensing layer at the back of the eye. Though uncommon, it is the most common eye cancer in childhood, typically affecting children under age 5. With early detection and modern treatment, survival rates are very high, often exceeding 95% in specialized care centers.

  • 4

    Retinopathy of prematurity

    Retinopathy of prematurity is an eye disease that affects babies born too early. While most cases resolve on their own, some require treatment to prevent vision loss or blindness. Early screening and timely care can protect a baby’s sight.

  • 0

    Retinopathy proliferative

    Proliferative retinopathy is an advanced and serious complication of diabetes that can lead to blindness if left untreated, but with early detection and proper treatment, vision loss can often be prevented or slowed.

  • 2

    Retroperitoneal cancer

    Retroperitoneal cancer is a rare group of tumors that develop in the back of the abdomen, often growing silently to very large sizes before they are discovered. Understanding this uncommon disease and finding expert care can make a critical difference in treatment outcomes.