Bleeding

Also called: Hematoma, Hemorrhage

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Summary

Bleeding is the loss of blood. It can be external, or outside the body, like when you get a cut or wound. It can also be internal, or inside the body, like when you have an injury to an internal organ. Some bleeding, such as gastrointestinal bleeding, coughing up blood, or vaginal bleeding, can be a symptom of a disease.

Normally, when you are injured and start bleeding, a blood clot forms to stop the bleeding quickly. Afterwards, the clot dissolves naturally. To be able to make a clot, your blood needs blood proteins called clotting factors and a type of blood cell called platelets. Some people have a problem with clotting, due to another medical condition or an inherited disease. There are two types of problems:

Your blood may not form clots normally, known as a bleeding disorder. This happens when your body does not make enough platelets or clotting factors, or they don't work the way they should.
Your blood may make too many clots, or the clots may not dissolve properly

Sometimes bleeding can cause other problems. A bruise is bleeding under the skin. Some strokes are caused by bleeding in the brain. Severe bleeding may require first aid or a trip to the emergency room.

Start Here

Internal Bleeding (Merck & Co., Inc.) Also in Spanish

Diagnosis and Tests

Blood Test: Factor VIII Activity (Nemours Foundation) Also in Spanish
Blood Test: Prothrombin Time (PT) (Nemours Foundation) Also in Spanish
Partial Thromboplastin Time (PTT) Test (National Library of Medicine) Also in Spanish

Treatments and Therapies

Severe Bleeding: First Aid (Mayo Foundation for Medical Education and Research) Also in Spanish
What Do I Need in My First Aid Kit? (American Academy of Family Physicians) Also in Spanish

Specifics

About Vitamin K Deficiency Bleeding (Centers for Disease Control and Prevention) Also in Spanish
Anemia Due to Excessive Bleeding (Merck & Co., Inc.) Also in Spanish
Blood in Urine (National Library of Medicine) Also in Spanish
Gastrointestinal Bleeding: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish
Intracranial Hematoma (Mayo Foundation for Medical Education and Research) Also in Spanish
Nosebleeds (American Academy of Family Physicians) Also in Spanish
Subconjunctival Hemorrhage (Broken Blood Vessel in Eye) (Mayo Foundation for Medical Education and Research)
Vaginal Bleeding: MedlinePlus Health Topic (National Library of Medicine) Also in Spanish

Genetics

Warfarin sensitivity: MedlinePlus Genetics (National Library of Medicine)

Videos and Tutorials

Blood clotting (Medical Encyclopedia) Also in Spanish

Clinical Trials

ClinicalTrials.gov: Hematoma (National Institutes of Health)
ClinicalTrials.gov: Hemorrhage (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

Reference Desk

Hematology Glossary (American Society of Hematology)

Find an Expert

Find a Hematologist (American Society of Hematology)
National Heart, Lung, and Blood Institute

Children

Blood in the Urine (Hematuria) (For Parents) (Nemours Foundation) Also in Spanish
Dealing with Cuts (For Parents) (Nemours Foundation) Also in Spanish
Embolization (For Parents) (Nemours Foundation) Also in Spanish
Nosebleeds (Nemours Foundation) Also in Spanish
Nosebleeds (For Parents) (Nemours Foundation) Also in Spanish
What's a Scab? (Nemours Foundation) Also in Spanish

Teenagers

Nosebleeds (Nemours Foundation) Also in Spanish

Patient Handouts

Bleeding (Medical Encyclopedia) Also in Spanish
Bleeding gums (Medical Encyclopedia) Also in Spanish
Bleeding into the skin (Medical Encyclopedia) Also in Spanish
Intraventricular hemorrhage of the newborn (Medical Encyclopedia) Also in Spanish
Subarachnoid hemorrhage (Medical Encyclopedia) Also in Spanish