Hemorrhage- Definition, Class, Types, Disorders

Hemorrhage, commonly known as bleeding, means the escape of circulating blood from blood vessels due to the rupture of blood vessels.

Simply it is acute blood loss from the disrupted blood vessels. Depending on the degree and anatomical site of hemorrhage, it can be trivial to fatal. Physical damage/stresses/trauma, as well as physiological disorders, can induce hemorrhage.


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Hemorrhage Class

  • Out of about 5 liters of blood in an adult average, a loss of about 15% (about 750 mL) produces no physical symptoms, and one can easily tolerate this much blood loss. This kind of hemorrhage is called a Class I hemorrhage.
  • Loss of 15% to 30% of total blood is called a Class II hemorrhage. Patients of class II hemorrhage experience nausea, fatigue, weakness, tachycardia (increased heart rate) with about 100 to 120 beats per minute, and tachypnea (increased breathing rate) with about 20 to 24 breaths per minute.
  • Loss of 30% to 40% of blood is called a Class III hemorrhage. Patients of class III hemorrhage experience nausea, fatigue, tachycardia with more than 120 beats per minute, tachypnea with more than 24 breaths per minute, drastic blood pressure drop and deviation, narrow pulse pressure, and change in mental status.
  • Loss of more than 40% of blood is called a Class IV hemorrhage. Besides symptoms of the Class III hemorrhage, a patient will show severe oliguria (decreased urine output), excessively low amount of blood (hypovolemia), and negligible peripheral pulse pressure. Slowly, the patient will go into a coma, and organ failure will occur leading slowly to death. Such death due to excessive blood loss is called exsanguination.
  • If the bleeding is internal i.e. within the body then such hemorrhage is called internal hemorrhage. Such hemorrhages are difficult to detect and can cause deposition of blood and blood clots within tissues and internal organs leading to death. Whereas, if the bleeding is outside the body, then such bleeding is called external hemorrhage. 
  • Traumatic injury, cutting, fracture, high blood pressure, ulcers, cancer, hematological diseases, hereditary disease like hemophilia, several infections (hemorrhagic infections), deep bites, blood clotting disorders, surgery, and surgical complications, etc. are common causes of hemorrhage.

Types of Hemorrhage

Based on the anatomical location of bleeding, hemorrhage can be of diverse types. Some common types of hemorrhage are: 

Bruise (hematoma): Bleeding underneath the skin forming blue to black spot

Epistaxis: Bleeding from the nose

Hematemesis: Vomiting of blood

Hemoptysis: Coughing of blood

Brain hemorrhage: Bleeding in the brain

Pulmonary hemorrhage: Blood in the lungs  

Hematuria: Blood in urine

Intracranial hemorrhage: Bleeding within the cranium

Gastrointestinal bleeding: Bleeding within the GI tract

Vaginal bleeding: Bleeding from the vagina

Melena: Bleeding within the upper GI tract

Hemorrhagic Disorders

There are certain conditions when the body can’t prevent the bleeding and/or the body will form a blood clot within the vessel without any hemorrhage. Such conditions can be described as hemorrhagic or hemostasis disorders.

Some common hemostasis disorders are:

  • Thrombosis: It is the condition of the formation of a blood clot within the blood vessels. If the clot is formed inside veins obstructing the blood flow, then the condition is defined as a thrombotic disorder.
    Similarly, when a blood clot forms inside the artery and blocks the arterial blood flow, then the condition is defined as an embolism. It may result in stroke and pulmonary embolism.
  • Hemophilia: It is genetic a hemorrhagic disorder characterized by the body’s inability of forming blood clots resulting in uncontrolled blood loss. It is an inheritable genetic disorder caused due to mutation or change in a gene that encodes for clotting factors in X-chromosome; hence it is categorized as an X-linked sex-linked genetic disorder. Therefore, it is seen in males only, while females are asymptomatic carriers.
    Hemophilia A and hemophilia B are the two most common hemophilia types that are caused by scarcity (absence) of clotting factor VIII and clotting factor IX respectively.
    It results in uncontrolled blood loss due to the inability of the body to form a clot. Common symptoms include bruising or hematoma, bleeding in joints, bleeding for a long period after a minor injury like an injection of a needle or prickling of a finger, hematuria, hematochezia, difficult-to-control epistaxis, etc. 
    The condition can be genetically diagnosed, by studying the clotting factors in the blood, or by the study of blood clotting time. Replacing the lacking or the absent blood clotting factor, gene therapy, and administration of monoclonal antibodies are the best ways to treat patients with hemophilia.
  • Von Willebrand Disease (VWD): It is a common genetic hemorrhagic disorder caused due to scarcity of the von Willebrand factors (VWFs) or a decrease in the functioning of the VWFs. The scarcity or decrease in the functioning of VWFs decreases platelet adhesions and the formation of a blood clots. VWD is of three types; type I VWD caused due to partial deficiency of the VWFs, type II VWD is caused due to inability of VWFs to function properly, and type III VWD is caused due to complete absence of detectable VWFs.
  • Hypercoagulability: Also called thrombophilia, is a hemorrhagic disorder characterized by the increased tendency of blood to clot.
  • Hypocoagulability: It is a hemorrhagic disorder characterized by the decreased ability of blood to clot.


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About Author

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Prashant Dahal

Prashant Dahal completed his bachelor’s degree (B.Sc.) Microbiology from Sunsari Technical College, affiliated with Tribhuvan University. He is interested in topics related to Antimicrobial resistance, the mechanism of resistance development, Infectious diseases (Pneumonia, tuberculosis, HIV, malaria, dengue), Host-pathogen interaction, Actinomycetes, fungal metabolites, and phytochemicals as novel sources of antimicrobials and Vaccines.

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