Leukopenia is a relatively common hematological disease that can occur at any age. It is characterized by a persistent peripheral blood white blood cell count below 4×10^9/L. The onset of the disease is mostly slow, with mild symptoms. Common symptoms include fatigue, palpitations, dizziness, and pharyngitis, making individuals more susceptible to pharyngitis or mucosal ulceration. Other symptoms include reduced appetite, limb soreness, insomnia, and frequent dreaming. Individuals with leukopenia are also more prone to viral and bacterial infections. Some infections can lead to severe symptoms such as high fever, chills, and body aches. However, if there is a significant decrease in the total number of white blood cells, with the absolute neutrophil count dropping below 0.5×10^9/L, this condition is referred to as neutropenia. In such cases, symptoms may include chills, high fever, sore throat, headache, joint pain, and in severe cases, it can even lead to death.