Browse All Conditions

Explore 28,964 medical conditions with active and completed U.S. clinical trial data drawn from ClinicalTrials.gov, the U.S. National Institutes of Health public registry. According to ClinicalTrials.gov, the National Institutes of Health public registry maintained by the U.S. National Library of Medicine catalogs more than 500,000 clinical studies across over 220 countries since 1997, with the U.S. Food and Drug Administration Amendments Act (FDAAA) of 2007 requiring registration for most studies of FDA-regulated products. See our methodology for refresh cadence.

PlainTrial's condition directory indexes every disease, disorder, syndrome, and medical condition with at least one clinical study registered on ClinicalTrials.gov. Each entry links to a per-condition profile page showing recruiting trials, completed studies, phase distribution, sponsor mix, and geographic coverage. We use the MeSH-aligned condition names submitted by trial sponsors to the National Library of Medicine, so a condition you find here is the same condition a clinician would search on PubMed or a researcher would tag in a grant application.

Use the alphabetical index to browse the full list, or sort by trial volume to find conditions with the deepest active research pipelines. Conditions with a "Recruiting" count in the third column have at least one trial currently enrolling participants - click through to see locations and eligibility. Conditions with high trial counts but zero recruiting slots usually reflect a maturing pipeline (Phase 3 studies are enrollment-closed) or a condition where standard-of-care has shifted research focus to combination therapies and post-approval surveillance.

The directory is comprehensive but not equally deep across conditions. Rare diseases may show fewer than a handful of trials because patient populations are limited - this is a feature of clinical research, not an indexing gap on our end. Common conditions (cancer subtypes, diabetes, hypertension, depression) show dozens to hundreds of studies because they attract the broadest sponsor investment. Every number on this page comes directly from ClinicalTrials.gov; we do not manually edit counts, and we update from the NLM bulk-export on a regular cadence so what you see reflects the most recent registry state we have ingested.

Breast Cancer1,251Healthy1,096Obesity1,057Prostate Cancer749Depression687Cancer621HIV Infections615Hypertension472Stroke456Non-Small Cell Lung Cancer450
A2,832B1,103C2,954D1,173E990F827G777H1,716I1,113J83K188L1,242M2,127N1,045O826P2,857Q24R1,694S3,019T976U530V511W241X47Y19Z17
Treemap Treemap of 10 categories, sized proportional to value. Breast Cancer - 1,251 Breast Cancer 1,251 Healthy - 1,096 Healthy 1,096 Obesity - 1,057 Obesity 1,057 Prostate Cancer - 749 Prostate Cancer 749 Depression - 687 Depression 687 Cancer - 621 Cancer 621 HIV Infections - 615 HIV Infections 615 Hypertension - 472 Hypertension 472 Stroke - 456 Stroke 456 Non-Small Cell Lung Cancer - 450 Non-Small Cell Lu… 450

28,964 conditions

Sort by: Name Most Trials Recruiting
Condition Trials
Low Fitness 1
Low Fluid Intake, Chronic 1
Low Grade Astrocytoma 2
Low Grade B-cell Lymphoma, Not Otherwise Specified 1
Low Grade CNS Tumors 1
Low Grade Fallopian Tube Serous Adenocarcinoma 1
Low Grade Glioma 24
Low Grade Glioma (LGG) of Brain With BRAF Aberration 1
Low Grade Glioma of Brain 3
Low Grade Glioma of Brain With Neurofibromatosis Type 1 1
Low Grade Lung Neuroendocrine Neoplasm 1
Low Grade Non-Hodgkin's Lymphoma, Adult 1
Low Grade Ovarian Serous Adenocarcinoma 3
Low Grade Prostate Cancer 1
Low Grade Serous Carcinoma 1
Low Income Population 4
Low Mood 1
Low Ovarian Reserve 1
Low Physical Fitness 3
Low Positive Affect 1
Low Risk 1
Low Risk Myelodysplastic Syndromes 1
Low Risk Prostate Cancer 1
Low T3 Syndrome 1
Low Testosterone 1
Low Urine Volume 1
Low Ventricular Filling Pressures (Preload Failure) 1
Low Vision 9
Low Vision Aids 2
Low Vision Blindness 1
Low Weight Eating Disorders 1
Low Whole Grain and High Sugar 1
Low Whole Grain and Low Sugar 1
Low-CSD Melanoma 1
Low-Density-Lipoid-Type Hyperlipoproteinemia 1
Low-Dose Liver Radiation (LD-LRT) 1
Low-Frequency Residual Hearing 1
Low-Grade Lymphoma 1
Low-grade NMIBC 1
Low-Grade Serous Ovarian Cancer 3
Low-grade Upper Tract Urothelial Carcinoma 2
Low-Level Laser Therapy 1
Low-pass Filtering Speech 1
Low; Birthweight, Extremely (999 Grams or Less) 1
Lowe Syndrome 1
Lower Alveolar Ridge Squamous Cell Carcinoma 1
Lower Back Pain 5
Lower Back Pain Chronic 1
Lower Extremity 2
Lower Extremity Acute Limb Ischemia 1