Platelet count(PLT)is one of the most usual blood tests. When the PLT is lower than the normal reference value, people always worry about it. However this fear is unnecessary in most cases. It is common for domestic doctors to overtreat "thrombocytopenia" .

Platelets are the cytoplasmic fragments of megakaryocytes in the blood circulatory system.One of its main functions is to stop the bleeding.When the vessel wall is damaged, the hemostasis begins.The initial step of hemostasis is platelet adhere to the subcutaneous of vessels, and then the interaction between platelet to platelets is initiated. At the same time, platelets release their internal granules, thereby increasing the aggregation of platelets in the cycle.Finally, platelet embolus is formed to plug the damaged vessel wall and lead to further hemostasis.

    Platelets are indispensable in hemostasis. But in hemostasis, the PLT does not necessarily require a "high value" . The normal reference value of our platelet count is investigated by the crowd. Detect healthy people Randomly and removie those "2.5% of low PLT + 2.5% of high PLT", which is what we call normal reference value. The current reference limit for platelet count is 100×10^9/L . However, clinical studies have confirmed that, in most cases, we don't need so high platelet count to stop the bleeding.

    According to the consensus of several studies: In order to reduce the risk of bleeding, the "platelet target values" are different in different situations.

1. No fever, no surgery and parturition, the platelet count can be as low as 10 x 10 ^ 9 / L. That is to say, if PLT is below this value, it should be actively intervened the treatment. Otherwise there may be a risk of spontaneous bleeding.

2. If there is fever, surgery, parturition or other blood clotting disease, the number of platelet counts should be higher, otherwise the risk of bleeding will be high.

Are you surprised by all these?Can platelets be so low? Of couse yes, The platelet count can be so low!

    The most common cause of thrombocytopenia is Immune thrombocytopenia (ITP). In the past, it was called idiopathic thrombocytopenic purpura (ITP). It has a fairly high self-healing rate in children. There is a considerable proportion of adults who can heal by themselves. As a self-healing disease, ITP is often over-treated.

    First, the "platelet count" of the ITP patients does not need to be restored to normal reference values. Because ITP patients can tolerate low levels of platelet count. As long as the platelet count in more than 10 x 10 ^ 9 / L, the patients just need to be observed, unless there is a obvious bleeding tendency, fever, surgery, and to have children. When the platelet count is more than 30 x 10 ^ 9 / L, it does not be too anxious. 

    In fact, the target value of the platelet of ITP is 30 x 10 ^ 9 / L, therefore, most of the ITP patients are not need to be treated!

    In our real life, a large number of ITP patients have set a false "platelet count target". Therefore, the treatment regimens with huge side effects are abused by many ITP patients, such as glucocorticoids, immunosuppressants and so on.

    The "target value of platelet count" in ITP patients was basically induced by doctors. Why this phenomena is so common? I think not only the doctors but also ourselves need to rethink.