What is overt bleeding?

Definition of Overt Bleeding

Overt bleeding is defined as any clinically obvious source of bleeding or bleeding source identified after appropriate investigation and diagnostic testing (e.g., imaging), including any procedural blood loss. 1

Core Definition

The Valve Academic Research Consortium 3 (VARC-3), published in the Journal of the American College of Cardiology, provides the authoritative definition used in cardiovascular clinical research and practice. 1

Key characteristics of overt bleeding include:

• Clinically visible bleeding that is apparent to the patient or healthcare provider 1
• Bleeding identified through diagnostic testing such as imaging studies, even if not initially visible 1
• Any procedural blood loss that occurs during medical interventions 1

Clinical Presentation

Overt bleeding manifests with visible signs that distinguish it from occult bleeding:

• Hematemesis (vomiting blood) 1
• Melena (black, tarry stools) 1
• Hematochezia (bright red blood per rectum) 1
• Visible bleeding from surgical sites, access sites, or wounds 1

This contrasts with occult bleeding, where patients have guaiac-positive stools or iron deficiency anemia without visible blood loss. 1

Classification Framework

The VARC-3/BARC classification system categorizes overt bleeding by severity, with all types requiring visible or documented bleeding: 1, 2, 3

Type 1 (Minor)

• Overt bleeding requiring medical intervention by a healthcare professional, leading to hospitalization, increased level of care, or medical evaluation 1, 2
• Overt bleeding requiring transfusion of 1 unit of whole blood/red blood cells 1, 2

Type 2 (Major)

• Overt bleeding requiring transfusion of 2-4 units of whole blood/red blood cells 1, 2
• Overt bleeding with hemoglobin drop >3 g/dL but <5 g/dL 1, 2

Type 3 (Life-threatening)

• Overt bleeding in critical organs (intracranial, intraspinal, intraocular, pericardial with tamponade, intramuscular with compartment syndrome) 1, 2
• Overt bleeding causing hypovolemic shock or severe hypotension (systolic BP <90 mmHg lasting >30 minutes, not responding to volume resuscitation) or requiring vasopressors 1, 2
• Overt bleeding requiring reoperation or surgical intervention for control 1, 2
• Overt bleeding requiring transfusion ≥5 units of whole blood/red blood cells 1, 2
• Overt bleeding with hemoglobin drop ≥5 g/dL 1, 2

Type 4 (Fatal)

• Overt bleeding leading to death, either probable (clinical suspicion) or definite (confirmed by autopsy or imaging) 1, 2

Clinical Context

The timing and documentation of overt bleeding are critical:

• Bleeding should be documented within 48 hours of index procedure, during total index hospitalization, and during any subsequent hospitalizations 1, 2
• Physiological parameters including vital signs, signs of hypovolemia, and required interventions must be recorded 2
• The duration and pattern (immediate, delayed, or recurrent) should be specified 2

Common Pitfalls

Do not confuse overt with occult bleeding: Occult bleeding lacks visible blood and presents only with positive fecal occult blood testing or unexplained anemia. 1 Overt bleeding always has a visible or imaging-documented source. 1

Emergency timing matters: In gastrointestinal bleeding, emergency endoscopy performed within 24-72 hours of overt bleeding has significantly higher diagnostic yields (70-93%) compared to delayed procedures (30-64%). 4, 5 This emphasizes the importance of recognizing and acting on overt bleeding promptly.