Which diseases get the most clinical trials?

About 85,000 clinical trials registered on ClinicalTrials.gov as of November 2026 study cancer and other tumors, more than any other disease group; brain and nerve diseases come next with about 57,000. Groups are the National Library of Medicine's disease categories, and a trial counts in every group its conditions fall under, so the bars add up to more than the total.

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Bars are sorted from highest to lowest and start at zero; each one's value is at its end.

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Key facts

Measure: Clinical trials (all years). Written from the data below.

  • Cancer and other tumors has the highest figure, 84,658, followed by Brain and nerve diseases (56,897) and Heart and blood vessel diseases (44,227).
  • Ear, nose and throat diseases has the lowest figure, 5,869, followed by Mouth and teeth diseases (10,158) and Eye diseases (10,873).
  • The highest is 14 times the lowest.

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Source and date

Source
ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2
License
Public domain (U.S. government work); source National Library of Medicine
Data as of
Published

Citation

Chartly. “Which diseases get the most clinical trials?” Chart. Data: ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2, https://clinicaltrials.gov/data-api/api (data as of November 3, 2026). https://chart.ly/charts/clinical-trials-by-condition (accessed November 4, 2026).

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The data

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The file has the numbers in this table, with the source, license and date. Please credit the source and Chartly. Developers can also get them as JSON (how).

Disease group Clinical trials (all years)
Cancer and other tumors 84,658
Brain and nerve diseases 56,897
Heart and blood vessel diseases 44,227
Kidney, urinary and genital diseases 41,032
Mental health conditions 40,599
Metabolic diseases, incl. diabetes and obesity 38,912
Lung and airway diseases 37,527
Immune system diseases 37,041
Digestive diseases 34,020
Infections 33,518
Skin and connective tissue diseases 29,657
Hormone (endocrine) diseases 27,519
Pregnancy complications 27,477
Blood diseases 23,446
Bone, joint and muscle diseases 20,795
Inherited and newborn conditions 16,520
Injuries 16,478
Eye diseases 10,873
Mouth and teeth diseases 10,158
Ear, nose and throat diseases 5,869

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