2026 data ClinicalTrials.gov official source

Conditions: O

Compiled by PlainTrial · January 1, 2026

Every condition beginning with O that has a registered US clinical trial, with how many studies cover each.

820 conditions starting with "O"

Showing 651–700 of 820

Condition	Trials	Recruiting
Other Solid Tumors	4	3
Other Solid Tumors, Adult	2	1
Other Specified Bipolar and Related Disorder	1	1
Other Specified Feeding or Eating Disorder	1	1
Other Specified Injury of Thoracic Aorta	1	-
Other Specified Respiratory Problems in Fetus or Neonate	1	-
Other Specified Schizophrenia Spectrum and Other Psychotic Disorder	1	-
Other Surgical Procedures	1	-
Other Symbolic Dysfunctions	1	1
Other Tumors	1	1
Other Tumors With EGFR Dependence	1	-
Otitis	1	-
Otitis Externa	1	-
Otitis Media	16	4
Otitis Media Acute	2	1
Otitis Media in Children	1	-
Otitis Media Recurrent	1	-
Otitis Media With Effusion	6	2
Otitis Media, Secretory	1	-
Otitis Media, Serous	1	-
Otolaryngological Disease	2	1
Otomycosis	1	1
Otorhinolaryngologic Disease	1	-
Otorhinolaryngologic Diseases	2	-
Otorhinolaryngologic Neoplasm	1	-
Otosclerosis	1	-
Ototoxicity	4	1
Ototoxicity, Drug-Induced	1	1
Oular Hypertension	1	-
Out-Of-Hospital Cardiac Arrest	5	2
Outbreak Investigation	2	1
Outcome	1	1
Outcome Assessment	1	-
Outcome Monitoring	1	-
Outcomes	1	-
Outpatient	1	-
Outpatient Colonoscopy for Colorectal Cancer Screening or for Symptoms Suggestive of Colonic Diseases	1	-
Outpatient Parenteral Antibiotic Therapy	1	-
Outreach Intervention	1	-
Ovarian	1	-
Ovarian Aging	2	2
Ovarian Brenner Tumor	5	-
Ovarian Cancer	338	147
Ovarian Cancer (OvCa)	1	1
Ovarian Cancer Metastatic	1	1
Ovarian Cancer Metastatic Recurrent	1	1
Ovarian Cancer Recurrent	5	3
Ovarian Cancer Stage 1	1	1
Ovarian Cancer Stage 3	1	1
Ovarian Cancer Stage II	1	1

Data sourced from official public datasets. See our methodology for details.