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 751–800 of 820

Condition	Trials	Recruiting
Ovarian Undifferentiated Adenocarcinoma	2	-
Ovarian Undifferentiated Carcinoma	2	-
Ovarian Yolk Sac Tumor	1	-
Ovarian, Fallopian Tube and Primary Peritoneal Carcinoma	1	-
Ovarian, Fallopian Tube, and Primary Peritoneal Cancer	1	-
Ovarian/Peritoneal/Fallopian Cancer	1	1
Ovary Cancer	11	6
Ovary Neoplasm	1	1
Ovary; Anomaly	1	1
Over Age 60	1	-
Over Age 75	1	1
Overactive Bladder	48	21
Overactive Bladder (OAB)	8	7
Overactive Bladder (OAB) With Symptoms of Frequency, Urgency, and Urgency	1	-
Overactive Bladder Syndrome	13	8
Overactive Detrusor	2	1
Overall Survival	1	1
Overdose	14	4
Overdose Accidental	4	2
Overdose Antidote	1	-
Overdose Cocaine	1	-
Overdose Methamphetamine	1	-
Overdose of Opiate	2	1
Overdose, Drug	1	-
Overeating	4	1
Overheating	1	-
Overlap Syndrome	2	2
Overnutrition	1	1
Oversensing Cardiac Pacemaker	1	-
Overuse Injury	2	-
Overuse Syndrome	1	-
Overweight	198	50
Overweight (BMI > 25)	4	2
Overweight (BMI > 25)	2	1
Overweight Adolescents	4	2
Overweight and Obese Adults	1	1
Overweight and Obese Women	1	1
Overweight and Obesity	116	40
Overweight or Obese	2	1
Overweight or Obese Adults	3	2
Overweight or Obese, Type 2 Diabetes	1	1
Overweight or Obesity	33	19
Overweight or Obesity and Elevated Liver Fat	1	1
Overweight With Diabetes	1	1
Overweight With One Weight Related Comorbidity	1	-
Overweight, Childhood	3	2
Overweight, Obesity and Other Hyperalimentation (E65-E68)	1	-
Overweight, Obesity, Small for Gestational Age, Prematurity	1	-
Overweight/Obese Women	1	-
Overweight/Obesity	1	1

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