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

  • 5

    Pre-eclampsia

    Pre-eclampsia is a serious blood pressure condition that can develop during pregnancy, typically after the 20th week, affecting 5% to 8% of all pregnancies and posing risks to both mother and baby if left untreated.

  • 1

    Precocious puberty

    When children’s bodies begin developing into adult bodies much earlier than expected, it can raise concerns and questions for families. Understanding what is happening and why can help parents support their child through this challenging time.

  • 1

    Precursor B-lymphoblastic lymphoma

    Precursor B-lymphoblastic lymphoma is a rare and uncommon blood cancer that primarily affects lymph nodes and tissues outside the bone marrow, with a distinct preference for locations beyond typical blood-forming organs.

  • 0

    Precursor B-lymphoblastic lymphoma recurrent

    When B-lymphoblastic lymphoma returns after treatment, patients face challenging decisions about next steps. Understanding what happens when this aggressive blood cancer comes back can help patients and families navigate treatment options and maintain hope.

  • 0

    Precursor B-lymphoblastic lymphoma refractory

    When precursor B-cell lymphoblastic lymphoma stops responding to treatment, patients face one of the most challenging situations in cancer care, with traditional chemotherapy offering limited hope for long-term survival.

  • 0

    Precursor T-lymphoblastic lymphoma/leukaemia recurrent

    When precursor T-lymphoblastic lymphoma or leukaemia returns after treatment, patients face one of the most challenging situations in blood cancer care, with survival rates remaining significantly lower than for newly diagnosed disease.

  • 0

    Precursor T-lymphoblastic lymphoma/leukaemia refractory

    When T-cell acute lymphoblastic leukaemia or lymphoblastic lymphoma does not respond to treatment, patients face one of the most challenging situations in blood cancer care, with survival rates remaining below 30%.

  • 0

    Premature baby

    When a baby arrives before completing 37 weeks in the womb, they need special attention and care to grow and thrive. These tiny fighters face unique challenges, but with modern medical care and dedicated support, most can overcome early obstacles and develop into healthy children.

  • 2

    Premature rupture of membranes

    Premature rupture of membranes occurs when the fluid-filled sac protecting a baby breaks before labor begins, creating risks for both mother and child that require immediate medical attention and careful management decisions.

  • 2

    Preterm premature rupture of membranes

    Preterm premature rupture of membranes (PPROM) occurs when the protective sac surrounding your baby breaks before 37 weeks of pregnancy and before labor begins. This complication affects about 3% of pregnancies and requires careful medical management to balance the risks of premature birth against the dangers of infection and other complications.

  • 2

    Primary adrenal insufficiency

    Primary adrenal insufficiency, also known as Addison’s disease, is a rare but serious condition where your adrenal glands cannot produce enough of the essential hormones cortisol and aldosterone. Though uncommon, affecting about 1 in 100,000 people in the United States, this condition requires lifelong treatment and careful management to prevent life-threatening complications.

  • 2

    Primary amyloidosis

    Primary amyloidosis, also known as AL amyloidosis, is a rare disorder where abnormal proteins build up in organs and tissues throughout the body, potentially affecting the heart, kidneys, nerves, and other vital systems.

  • 7

    Primary biliary cholangitis

    Primary biliary cholangitis is a long-term liver condition where the immune system mistakenly attacks the small tubes in the liver that carry bile, leading to gradual damage that can worsen over time without treatment.

  • 3

    Primary hyperaldosteronism

    Primary hyperaldosteronism is a condition where your adrenal glands produce too much of a hormone called aldosterone, leading to high blood pressure and potentially serious health problems. Once considered rare, it is now recognized as one of the most common causes of high blood pressure that doesn’t respond well to medication, affecting up to 10% of people with hypertension.

  • 2

    Primary hypercholesterolaemia

    Primary hypercholesterolaemia is a condition where your blood contains too much “bad” cholesterol, specifically low-density lipoprotein (LDL). While it usually causes no symptoms, it silently increases your risk of heart attacks and strokes by allowing fat to build up in your arteries.

  • 2

    Primary hyperoxaluria

    Primary hyperoxaluria is a rare inherited condition where the body produces too much oxalate, leading to recurring kidney stones and potentially life-threatening kidney damage.

  • 1

    Primary hyperthyroidism

    Primary hyperthyroidism occurs when your thyroid gland itself produces too much thyroid hormone, speeding up your body’s metabolism and affecting nearly every organ system. This condition differs from secondary hyperthyroidism, where the problem starts in the pituitary gland.

  • 0

    Primary hypogonadism

    Primary hypogonadism is a condition where the testes fail to produce enough testosterone or sperm, affecting male development, sexual function, and overall health at any stage of life.

  • 6

    Primary immunodeficiency syndrome

    Primary immunodeficiency syndrome refers to a large group of disorders where the body’s immune system doesn’t work properly, making it harder to fight off infections and leading to various health complications throughout life.

  • 4

    Primary mediastinal large B-cell lymphoma

    Primary mediastinal large B-cell lymphoma is a rare and aggressive form of cancer that develops in the chest, primarily affecting young adults and showing a unique tendency to occur more often in women than men.

  • 1

    Primary mediastinal large B-cell lymphoma refractory

    Primary mediastinal large B-cell lymphoma (PMBCL) is an aggressive form of cancer that develops in the space between the lungs. While most patients respond well to initial treatment, those whose disease becomes refractory—meaning it no longer responds to standard therapy—face significant challenges that require specialized approaches.

  • 7

    Primary myelofibrosis

    Primary myelofibrosis is a rare blood cancer where excessive scar tissue builds up in the bone marrow, affecting the body’s ability to produce healthy blood cells and potentially leading to serious complications if left unmanaged.

  • 3

    Primary progressive multiple sclerosis

    Primary progressive multiple sclerosis is a type of multiple sclerosis where symptoms gradually worsen from the beginning, without the typical periods of symptom flare-ups and recovery seen in other forms of the disease. Unlike the more common relapsing-remitting MS, this progressive form affects about 10% of people diagnosed with MS and typically appears later in life.

  • 1

    Primitive neuroectodermal tumour

    Primitive neuroectodermal tumours are rare, aggressive cancers that develop from immature nerve cells left over from early development. While these tumours present significant treatment challenges, advances in medical understanding and treatment approaches are providing new hope for patients.

  • 0

    Prinzmetal angina

    Prinzmetal angina is a rare type of chest pain that strikes unexpectedly, usually during the night or early morning hours when you’re resting or asleep. Unlike typical angina that happens during physical exertion, this condition is caused by sudden spasms in the arteries supplying your heart with blood.

  • 2

    Procedural anxiety

    Fear and worry about medical procedures are common experiences that can affect anyone, from routine check-ups to complex surgeries. Understanding what procedural anxiety is and learning effective ways to manage it can help make medical visits less stressful and lead to better health outcomes.

  • 0

    Procedural haemorrhage

    Procedural haemorrhage is bleeding that occurs during or after a medical procedure. While common to most invasive procedures, the risk varies depending on the type of procedure, patient-specific factors, and the experience of the healthcare team performing the procedure.

  • 0

    Procedural headache

    Procedural headache is a type of headache that develops as a complication after certain medical procedures involving the spine, most commonly following a spinal tap or epidural anesthesia. This intense headache occurs when cerebrospinal fluid leaks through a puncture site in the protective covering of the spinal cord, causing pressure changes around the brain.

  • 0

    Procedural hypotension

    Procedural hypotension, also known as perioperative or intraoperative hypotension, is a common drop in blood pressure that occurs during surgery and anesthesia. This condition affects a significant number of surgical patients and can lead to serious complications if not properly managed.

  • 18

    Procedural pain

    Procedural pain is the discomfort children and adults experience during medical procedures like needle sticks, blood draws, and other medical interventions. While these procedures may be brief, their impact can extend far beyond the moment, affecting future healthcare experiences and overall well-being.

  • 4

    Prodromal Alzheimer’s disease

    Prodromal Alzheimer’s disease represents a critical window in the progression from normal cognition to dementia, when mild cognitive impairment begins to signal deeper brain changes that may lie ahead.

  • 1

    Progressive multifocal leukoencephalopathy

    Progressive multifocal leukoencephalopathy is a rare and often fatal brain infection caused by a common virus that most people carry harmlessly, but which can become dangerous when the immune system is severely weakened.

  • 9

    Progressive multiple sclerosis

    Progressive multiple sclerosis is a form of MS where symptoms gradually worsen over time, affecting about 10-15% of people diagnosed with multiple sclerosis. Understanding this condition and available treatments can help patients maintain quality of life.

  • 3

    Progressive relapsing multiple sclerosis

    Progressive relapsing multiple sclerosis is the rarest form of MS, affecting only about 5% of people with multiple sclerosis. Unlike other types, this condition combines steady worsening of symptoms from the start with occasional sudden flare-ups, making it particularly challenging to manage.

  • 6

    Progressive supranuclear palsy

    Progressive supranuclear palsy is a rare brain disease that primarily affects how you walk, move your eyes, think, and swallow. Although it shares some features with Parkinson’s disease, it progresses faster and has unique characteristics that set it apart.

  • 1

    Prolactin-producing pituitary tumour

    A prolactin-producing pituitary tumour, also called a prolactinoma, is the most common type of hormone-making tumour in the pituitary gland. These growths are not cancerous and often respond well to treatment with medication, though some people may need surgery.

  • 1

    Prolymphocytic leukaemia

    Prolymphocytic leukaemia is a rare and aggressive blood cancer that affects white blood cells. It advances rapidly and primarily affects older adults, making early diagnosis and treatment critical for managing this challenging condition.

  • 4

    Prophylaxis of nausea and vomiting

    Preventing nausea and vomiting, particularly after surgery, is a critical part of modern healthcare that can significantly improve patient comfort and reduce complications. Understanding available prevention strategies helps patients and healthcare providers work together to minimize these distressing symptoms.

  • 0

    Propionic acidaemia

    Propionic acidaemia is a rare inherited disorder where the body cannot properly break down certain proteins and fats, leading to a dangerous buildup of toxic acids that can cause serious health problems from the first days of life.

  • 73

    Prostate cancer

    Prostate cancer is one of the most common cancers affecting men worldwide, but many cases grow slowly and can be successfully managed with modern treatments and careful monitoring.

  • 32

    Prostate cancer metastatic

    Metastatic prostate cancer is cancer that begins in the prostate and spreads to other parts of the body, most often to the bones. While this advanced form cannot be cured, many treatments are available to control its growth, manage symptoms, and help patients live for years with a good quality of life.

  • 7

    Prostate cancer recurrent

    Recurrent prostate cancer means the cancer has returned after treatment. Up to 40% of men treated for prostate cancer will experience a recurrence, but many effective treatment options are available to control the disease and extend life.

  • 1

    Prostatitis Escherichia coli

    Prostatitis caused by Escherichia coli is a bacterial infection of the prostate gland that can lead to painful urination, pelvic discomfort, and flu-like symptoms. Understanding this condition helps patients recognize when to seek medical care and how treatment can effectively address the infection.

  • 1

    Proteinuria

    Proteinuria is the presence of an abnormal amount of protein in the urine, which can signal kidney damage or other health conditions. While healthy kidneys normally keep proteins in the blood and out of urine, damaged kidneys may allow protein to leak through, making proteinuria an important early warning sign of potential kidney problems.

  • 1

    Proteus syndrome

    Proteus syndrome is one of the world’s rarest genetic conditions, affecting fewer than 1 in 1 million people worldwide. This complex disorder causes some parts of the body to grow abnormally and out of proportion, leading to significant physical differences that worsen over time.

  • 2

    Pruritus

    Pruritus is the medical term for itching—an uncomfortable sensation that makes you want to scratch your skin. While everyone experiences itching at some point, chronic pruritus can be more than just a nuisance. It can disrupt sleep, affect mental health, and significantly impact quality of life, sometimes as much as chronic pain does.

  • 0

    Pseudomonas infection

    Pseudomonas infection is a condition caused by bacteria that are common in the environment but can become dangerous for people who are already ill or have weakened immune systems, potentially leading to life-threatening complications.

  • 2

    Pseudomyxoma peritonei

    Pseudomyxoma peritonei is a very rare cancer that fills the abdomen with a jelly-like substance. It usually begins in the appendix and slowly spreads within the belly, earning it the nickname “jelly belly.” Though challenging to diagnose early, modern treatments combining surgery and chemotherapy can offer hope for long-term survival.

  • 2

    Pseudoxanthoma elasticum

    Pseudoxanthoma elasticum is a rare genetic disorder that causes calcium and other minerals to accumulate in elastic tissues throughout the body, primarily affecting the skin, eyes, and blood vessels, and leading to a range of symptoms that require lifelong management.

  • 17

    Psoriasis

    Psoriasis is a chronic skin condition that causes thick, scaly patches to develop on the skin. While there’s no cure, many effective treatments can help manage symptoms and improve quality of life.

  • 5

    Psoriatic arthropathy

    Psoriatic arthropathy, also known as psoriatic arthritis, is a chronic inflammatory disease that causes pain, swelling, and stiffness in the joints. This condition often affects people who have psoriasis, a skin condition that creates scaly, itchy patches, although it can develop even without visible skin symptoms.

  • 1

    Psychogenic seizure

    Psychogenic seizures look and feel like epileptic seizures, but they are not caused by abnormal electrical activity in the brain. Instead, these episodes result from psychological distress and are real, involuntary events that can significantly disrupt daily life.

  • 0

    Psychological trauma

    Psychological trauma is an emotional response caused by severe distressing events that can affect anyone, leaving invisible wounds that may be more lasting than physical injuries. While most people experience natural recovery over time, understanding trauma and knowing effective ways to cope can help those struggling to reclaim their sense of safety and move forward.

  • 2

    Psychotic behaviour

    Psychotic behaviour occurs when people lose touch with reality, experiencing a disconnection that can involve seeing or hearing things that aren’t there, holding strong beliefs that aren’t true, or having confused patterns of thinking and speaking.

  • 9

    Psychotic disorder

    Psychotic disorders are serious mental illnesses where people lose touch with reality, experiencing false beliefs or perceiving things that aren’t there. These conditions affect how a person thinks, feels, and behaves, but with proper treatment, many people can recover and live full lives.

  • 0

    Pterygium

    Pterygium is a fleshy, triangular growth on the eye that develops mainly from prolonged sun exposure. While usually harmless, it can cause irritation and affect vision if left to grow across the cornea.

  • 0

    Pulmonary alveolar haemorrhage

    Pulmonary alveolar haemorrhage is a serious medical emergency where bleeding occurs within the tiny air sacs of the lungs, potentially causing severe breathing problems and requiring immediate medical attention.

  • 26

    Pulmonary arterial hypertension

    Pulmonary arterial hypertension is a serious condition where the small blood vessels in your lungs become narrow, making it harder for blood to flow through and causing your heart to work overtime.

  • 0

    Pulmonary congestion

    Pulmonary congestion is a serious condition where fluid accumulates in the lungs, making it difficult to breathe and preventing the body from getting enough oxygen. Understanding its causes, recognizing warning signs, and seeking prompt treatment can make a lifesaving difference.

  • 11

    Pulmonary embolism

    A pulmonary embolism is a serious medical emergency that occurs when a blood clot blocks an artery in the lungs, cutting off blood flow and oxygen supply. Quick treatment can save lives, but about 33% of people die before they receive diagnosis and treatment.