#Low Platelets

[mcatmemoranda]

●Definition – Thrombocytopenia (ie, platelet count <150,000/microL [150 x 109/L]) may be associated with a variety of conditions, with associated risks that range from life-threatening to none. We are most concerned about spontaneous bleeding with counts <10,000/microL, and surgical bleeding with counts <50,000/microL. Rarely, thrombocytopenia is associated with a risk of thrombosis rather than, or in addition to, bleeding. (See 'Definitions and areas of concern' above.)

●Causes – The potential causes of thrombocytopenia differ depending on the clinical setting in which it occurs (table 6). (See 'Causes of thrombocytopenia' above and 'Overview of our approach' above.)

•Severe thrombocytopenia with bleeding and certain causes of thrombocytopenia (suspected heparin-induced thrombocytopenia [HIT], thrombotic thrombocytopenic purpura [TTP], hemolytic uremic syndrome [HUS], drug-induced thrombotic microangiopathy [DITMA], or bone marrow failure syndrome with severe pancytopenia) are medical emergencies that require immediate action. (See 'Thrombocytopenic emergencies requiring immediate action' above.)

•In asymptomatic outpatients with thrombocytopenia, common diagnoses include immune thrombocytopenia (ITP), occult liver disease, HIV infection, and myelodysplastic syndromes. Congenital thrombocytopenias (sometimes misdiagnosed as ITP) may also occur (table 2). (See 'Asymptomatic, incidental finding, mild thrombocytopenia' above.)

•In patients with bleeding who lack signs of systemic illness or other abnormalities of the complete blood count (CBC), drug-induced immune thrombocytopenia (table 3) or primary ITP are likely diagnoses. (See 'Thrombocytopenia with bleeding or other symptoms' above.)

•In patients with other clinical findings, causes of thrombocytopenia include infection, sepsis, disseminated intravascular coagulation (DIC), drug-induced thrombocytopenia, HIT, liver disease, lymphoma, other malignancies, nutrient deficiencies (vitamin B12, folate, copper), TTP or HUS, antiphospholipid syndrome (APS), and paroxysmal nocturnal hemoglobinuria (PNH). (See 'Thrombocytopenia with bleeding or other symptoms' above.)

•In acutely ill patients, common causes of new-onset thrombocytopenia include sepsis, DIC, and drug-induced thrombocytopenia (table 1). Many patients in the intensive care unit with thrombocytopenia have more than one cause. (See 'Acutely ill/intensive care unit' above.)

●Evaluation – We confirm thrombocytopenia by repeating the CBC and reviewing the peripheral blood smear; obtain prior platelet counts, if available, and assess other hematologic abnormalities. The pace of the subsequent evaluation, further testing, and hematologist consultation depends on the clinical presentation, which can range from asymptomatic to acutely ill. (See 'Overview of our approach' above and 'Initial questions and pace of the evaluation' above.)

•History and examination – The history should focus on prior platelet counts, family history, bleeding, medications (table 3), over-the-counter remedies (table 4), infectious exposures, dietary practices, and other medical conditions (eg, hematologic disorders, rheumatologic conditions, surgery, transfusion). The physical examination should evaluate bleeding, lymphadenopathy, hepatosplenomegaly, thrombosis, and organ involvement. (See 'History' above and 'Physical examination' above.)

•Laboratory testing – No additional laboratory testing besides the CBC and peripheral blood smear is absolutely required in a patient with isolated thrombocytopenia. Adults with new thrombocytopenia should have HIV and HCV testing if not done recently. Additional laboratory testing may be warranted in patients with other findings. (See 'Laboratory testing' above.)

●Referral – Hematologist consultation is appropriate to confirm a new diagnosis or if the cause of thrombocytopenia is unclear. The urgency of referral depends on the degree of thrombocytopenia and other abnormalities, and the stability of the findings. In hospitalized patients, early hematology involvement is appropriate for individuals with suspected TTP, HUS, HIT, and some hematologic malignancies (eg, acute leukemia). (See 'Hematologist referral/consultation' above.)

●Bone marrow – Bone marrow evaluation is not required in all patients with thrombocytopenia; however, it may be helpful in some patients if the cause of thrombocytopenia is unclear, or if a primary hematologic disorder is suspected. (See 'Bone marrow evaluation' above.)

●Management – Management of patients with thrombocytopenia depends on the underlying diagnosis. General principles that apply to all patients include a review of medications that may interfere with normal hemostasis and a decision regarding whether they should be continued, coordination with anesthesiologists and surgeons before invasive procedures, and correction of coagulation abnormalities. Activity restrictions are often not needed. (See 'General management principles' above and "Platelet transfusion: Indications, ordering, and associated risks".)

●Other populations – Thrombocytopenia in neonates and children, and thrombocytopenia during pregnancy are discussed separately. (See "Neonatal thrombocytopenia: Etiology" and "Causes of thrombocytopenia in children" and "Thrombocytopenia in pregnancy".)

[boffincoderproducts]

Discovering low platelet count? Recognize symptoms like easy bruising, explore causes, and learn about effective treatments. Your health matters!

[byjove]

*doctor voice* we just got the test results back from your bloodwork and it’s weird. yeah. your blood is real freaking weird. what’s causing it? no clue. should you be worried about it? not really sure. anyway, just wanted to call and tell you your blood is all kinds of fucked up.

[carnage-cathedral]

my fucking spleen ??? really ?? the fuck even is a spleen ????

[epaulando]

blood bank rejected my blood because there was too much of it. my iron levels too high. my platelets too numerous. my veins too luscious. my plasma too nourishing. sad that they would discriminate against the sanguineously superior.

[trans-yllz]

woag my blood tests are already back... idk what they mean but I can look at them

[tchaikovskym]

Me to every doctor: I'm fine, I've never been finer, there is nothing wrong with me

My lab results: iron deficiency anaemia!

[woodfrogs]

small brain: my autoimmune condition symptoms appear when my body is fighting off an illness and ive just happened to be exposed to sick people a few days before my past two trips and no other times

huge brain: i have an autoimmune condition that acts up in anticipation of plane flights

[thateclecticbitch]

Motherfucker what is wrong with my blood this time?!?!

[mcatmemoranda]

Case study from today about a young guy with abdominal plain, jaundice, low platelets, hyperbilirubinemia. W/u for hepatitis, ITP, tick borne illnesses were negative. He was ultimately diagnosed with pylephlebitis. Treatment is antibiotics.

Bacteroides infection can make pts more likely to develop clots.

[boffincoderproducts]

Discovering the world of platelets is like unlocking a secret to our health. From a normal range of 150,000 to 450,000 platelets, understanding what's too low or too high empowers us to take charge of our well-being. Regular checks ensure these tiny blood heroes keep us healthy and thriving.

[toadsrbutch]

today on extremely niche hematology memes

[cavaliersecondary]

BEGGING WORKS my labs came back earlier than initially intended ALSO. ALSO they’re normal??? everything is in normal range?? EVERYTHING!! JAY HEALTH WIN!!!!

[villalunae]

my doctor literally told me i had way more platelets than normal and i was like huh thats weird. anyway time to deal with my weekly nosebleed

[chryzure-archive]

okay, good night! ( _ _ )...zzzZZ

[saintcentury]

We're at a blood drive. Why would I need a license to kill?