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
Condition Trials
Human Papilloma Virus Infection Type 18 1
Human Papilloma Virus Vaccine 2
Human Papilloma Virus Vaccine Hesitancy 1
Human Papillomavirus 13
Human Papillomavirus (HPV) 1
Human Papillomavirus (HPV)-Positive Oropharyngeal Cancer 1
Human Papillomavirus Infection 18
Human Papillomavirus Positive Anal Carcinoma 1
Human Papillomavirus Positive Cervical Carcinoma 1
Human Papillomavirus Positive Oropharyngeal Carcinoma 1
Human Papillomavirus Positive Oropharyngeal Squamous Cell Carcinoma 1
Human Papillomavirus Positive Penile Carcinoma 1
Human Papillomavirus Positive Vulvar Carcinoma 1
Human Papillomavirus Type 16 1
Human Papillomavirus Vaccination 3
Human Papillomavirus Vaccines 1
Human Papillomavirus Viruses 2
Human Papillomavirus-Independent Cervical Adenocarcinoma, Clear Cell-Type 1
Human Papillomavirus-Negative Neck Squamous Cell Carcinoma 1
Human Papillomavirus-Related Anal Squamous Cell Carcinoma 1
Human Papillomavirus-Related Carcinoma 8
Human Papillomavirus-Related Cervical Carcinoma 1
Human Papillomavirus-Related Cervical Squamous Cell Carcinoma 2
Human Papillomavirus-Related Malignant Neoplasm 1
Human Papillomavirus-Related Neck Squamous Cell Carcinoma of Unknown Primary 1
Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma 1
Human Papillomavirus-Related Squamous Cell Carcinoma of the Penis 1
Human Papillomavirus-Related Vulvar Squamous Cell Carcinoma 2
Human Papiloma Virus Vaccine 1
Human Parainfluenza Virus Type 3 1
Human Performance 1
Human Physiology 1
Human T-Lymphotrophic Virus Type I and/or Type II 1
Human T-lymphotropic Virus 1 1
Human T-lymphotropic Virus 2 1
Human Volunteers 1
Human-animal Interaction 1
Humans 1
Humeral Fracture, Proximal 1
Humeral Fractures 3
Humeral Fractures, Proximal 1
Humerus Fracture 2
Humerus Fractures 2
Humoral Hypercalcemia of Malignancy 1
Hunger 8
Hunter Syndrome 6
Huntington Disease 36
Huntington Disease, Late Onset 1
Huntington's Disease (HD) 1
Huntington's Dementia 1