It usually takes several weeks for a large hematoma to be absorbed.

When a hematoma is large, the absorption time generally depends on its location and specific condition. Typically, it takes 2–4 weeks, and up to 6 weeks at most. Hematomas can be classified according to their location into subcutaneous hematomas, epidural hematomas, retroperitoneal hematomas, etc.

1. Local subcutaneous hematoma

If the hematoma is large (over 5 cm), local aspiration under medical guidance followed by compression dressing is required, and absorption usually takes 2–4 weeks.

2. Epidural hematoma

If there is no pressure effect and the hematoma is small, conservative treatment may be adopted, with absorption generally occurring within 4–6 weeks. If the hematoma is large or severe, surgical intervention is necessary.

3. Retroperitoneal hematoma

This type is usually caused by trauma or postoperative bleeding. The management depends on the patient's specific condition. With conservative treatment, the hematoma is typically absorbed within 2–4 weeks. In severe cases, surgery is required.

If the hematoma is large, patients are advised to seek timely medical evaluation for further examination and receive appropriate treatment under the guidance of a qualified physician.