Which diseases get the most clinical trials?
About 84,000 clinical trials on ClinicalTrials.gov, roughly 1 in 5 of the 461,000 registered as of September 2026, study cancer or other tumors, more than any other disease group; brain and nerve diseases come next with about 56,000. 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.
The interactive chart needs JavaScript. The numbers are in the table below.
The value axis starts at zero. Hover, tap or use the arrow keys to read exact values.
Source and date
- Data as of
- Published
The data
| Disease group | Clinical trials (all years) |
|---|---|
| Cancer and other tumors | 84,074 |
| Brain and nerve diseases | 56,360 |
| Heart and blood vessel diseases | 43,878 |
| Kidney, urinary and genital diseases | 40,722 |
| Mental health conditions | 40,172 |
| Metabolic diseases, incl. diabetes and obesity | 38,644 |
| Lung and airway diseases | 37,256 |
| Immune system diseases | 36,833 |
| Digestive diseases | 33,805 |
| Infections | 33,324 |
| Skin and connective tissue diseases | 29,415 |
| Hormone (endocrine) diseases | 27,334 |
| Pregnancy complications | 27,242 |
| Blood diseases | 23,309 |
| Bone, joint and muscle diseases | 20,599 |
| Inherited and newborn conditions | 16,403 |
| Injuries | 16,306 |
| Eye diseases | 10,785 |
| Mouth and teeth diseases | 10,000 |
| Ear, nose and throat diseases | 5,820 |