What Are the Causes of a Decreased Platelet Count?

Platelet indices are an essential part of blood routine examination, as platelets play a crucial role in blood coagulation. However, a significant number of people experience a decrease in platelet count, and the reasons for this can vary among individuals, leading to different treatment approaches. Below is a summary of the causes of decreased platelet count.

1. Decreased platelet production or ineffective platelet death are major reasons for thrombocytopenia. These reasons can be further classified into genetic and acquired types. Acquired thrombocytopenia is caused by factors that affect platelet proliferation in the bone marrow or damage hematopoietic stem cells (such as infection, medication, malignancy, ionizing radiation, etc.).

2. Excessive destruction of platelets in the body is another cause of thrombocytopenia. This can be attributed to both congenital and acquired factors. Acquired platelet destruction can be further subdivided into immune and non-immune types. Common immune-mediated causes of excessive platelet destruction include drug-induced thrombocytopenia and idiopathic thrombocytopenic purpura.

3. Disorders in megakaryocyte maturation can also lead to thrombocytopenia. Since platelets and megakaryocytes share common antigens, anti-platelet antibodies can inhibit the maturation of megakaryocytes in the bone marrow, affecting platelet production.

Hazards of Thrombocytopenia:

1. Mucosal bleeding. Decreased platelet count increases the fragility of capillaries, leading to bleeding in other parts of the body, such as nasal bleeding, gingival bleeding, excessive menstrual bleeding, severe hematochezia, hematuria, and other systemic bleeding symptoms.

2. Inability to stop bleeding. At the site of small vessel rupture, platelets are unable to aggregate to form a platelet plug to block the rupture and release vasoconstrictive substances such as adrenaline and 5-hydroxytryptamine, resulting in failure of blood coagulation.

3. Susceptibility to purpura. Decreased platelet count weakens the permeability of capillaries, leading to the formation of purpura, usually in areas of loose skin such as the neck, eyes, and lower limbs. These areas may be accompanied by pain and swelling, and severe cases may manifest as purple patches in the oral mucosa.