00:00 / 00:00
Iron deficiency anemia
Anemia of chronic disease
Hemolytic disease of the newborn
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Autoimmune hemolytic anemia
Pyruvate kinase deficiency
Paroxysmal nocturnal hemoglobinuria
Sickle cell disease (NORD)
Anemia of chronic disease
Folate (Vitamin B9) deficiency
Vitamin B12 deficiency
Acute intermittent porphyria
Porphyria cutanea tarda
Vitamin K deficiency
Immune thrombocytopenic purpura
Thrombotic thrombocytopenic purpura
Von Willebrand disease
Disseminated intravascular coagulation
Antithrombin III deficiency
Factor V Leiden
Protein C deficiency
Protein S deficiency
Polycythemia vera (NORD)
Essential thrombocythemia (NORD)
Langerhans cell histiocytosis
Monoclonal gammopathy of undetermined significance
Microcytic anemia: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Macrocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Coagulation disorders: Pathology review
Platelet disorders: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
Lymphomas: Pathology review
Leukemias: Pathology review
Plasma cell disorders: Pathology review
Myeloproliferative disorders: Pathology review
0 / 11 complete
0 / 2 complete
|Prothrombin time (PT)||12 seconds|
|Activated partial thromboplastin time (aPTT)||29 seconds|
|Bleeding time*||15 minutes|
Elizabeth Nixon-Shapiro, MSMI, CMI
Jahnavi Narayanan, MBBS
The term heparin-induced thrombocytopenia can be divided into two parts.
Heparin refers to an anticoagulant medication which prevents blood clots from forming, and thrombocytopenia refers to decreased number of thrombocytes, or platelets, in the blood.
So, heparin-induced thrombocytopenia or, HIT, is a complication caused by heparin that results in decreased platelets in the blood.
Okay, so imagine you’re making dinner and accidentally cut one of your fingers.
Now, if your body doesn’t stop the bleeding, you will keep losing blood until there’s not enough to supply the vital organs like the heart and brain.
Now to prevent this from happening the body has a process called hemostasis.
This process has two phases: primary and secondary hemostasis.
In primary hemostasis, platelets aggregate to form a plug at the site of an injured blood vessel.
While these platelets are aggregating, coagulation, or secondary hemostasis starts.
This is where numerous enzymes that are always floating around in the blood called clotting factors get proteolytically activated, meaning that activation happens when a small piece is chopped off - a bit like pulling the pin out of a grenade.
These factors activate one another, eventually leading to the activation of fibrin or factor Ia.
That results in a fibrin mesh which forms around the platelet plug to reinforce it and hold it together.
Without primary and secondary hemostasis, our body would suffer massive blood loss from even the most minor injuries; imagine losing all of your blood from something as simple as a pinprick!
Heparin-induced thrombocytopenia (HIT) is a rare but potentially life-threatening complication that can occur during the treatment course with heparin. HIT occurs when the body produces antibodies against heparin, which then attach to and damage platelets (the cells that help the blood clot). This can decrease the number of platelets in the blood (thrombocytopenia), which can cause easy bruising and bleeding.
Copyright © 2023 Elsevier, except certain content provided by third parties
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.