Which is more severe, bruising or purpura?

Generally speaking, purpura is more severe than ecchymosis (bruising), with the following detailed explanation:

Ecchymosis primarily occurs during the early stage of subcutaneous bleeding, usually caused by trauma or other factors leading to rupture of capillaries. Blood extravasates from the ruptured capillaries into the subcutaneous tissue before it has fully dispersed, typically appearing blue or black; purpura indicates a relatively longer duration and more severe subcutaneous bleeding. When ecchymosis is not effectively treated or the bleeding worsens, hemoglobin within red blood cells can be further phagocytized by macrophages, causing the blood stasis to darken and form purple bruises.

In most cases, ecchymosis is caused by subcutaneous capillary rupture due to trauma and generally does not require special treatment, fading gradually over time. Long-standing purpura may suggest underlying pathological factors, such as idiopathic thrombocytopenic purpura, allergic purpura, coagulation factor deficiencies caused by various liver diseases, and hematologic disorders such as leukemia, lymphoma, aplastic anemia, and hemophilia.

During the initial phase after injury, cold compresses are recommended for ecchymosis to promote vasoconstriction and slow the bleeding. After 24 hours, warm compresses can be applied to improve local blood circulation and aid in dispersing the blood stasis. The same cold and warm compress methods can be used for treating purpura, but attention should be paid to monitoring any changes in the purpura. If purpura persists for a prolonged period or extensive bruising occurs, prompt medical consultation is necessary to undergo appropriate diagnostic tests and rule out the presence of hematologic diseases.