Hemorragia vs. sangramiento vs. sangrado
While 'hemorragia', 'sangramiento', and 'sangrado' can all refer to the bodily process of losing blood, they have different connotations and usage in the Spanish language.
Hemorragia
This term typically refers to a large amount of bleeding in a short period or internal bleeding. It often conveys a serious medical situation.
El cirujano trató de controlar la hemorragia durante la operación.
(The surgeon tried to control the hemorrhage during the operation.)
Una hemorragia cerebral puede ser fatal si no se trata a tiempo.
(A brain hemorrhage can be fatal if not treated immediately.)
Sangramiento
Sangramiento is a more general term indicating bleeding regardless of its intensity. It might be mild or severe depending on context, and can refer to both exterior and interior bleeding.
El sangramiento de una herida puede detenerse con presión.
(Bleeding from a wound can be stopped by applying pressure.)
El doctor está preocupado por un posible sangramiento interno.
(The doctor is worried about possible internal bleeding.)
Sangrado
'Sangrado' generally implies a less intense form of bleeding, often associated with small cuts, scrapes, nosebleeds, or menstrual flow.
Tengo un pequeño sangrado en el dedo por cortarme con un papel.
(I have a small bleeding on my finger from a paper cut.)
El sangrado menstrual puede variar de una mujer a otra.
(Menstrual bleeding may vary from woman to woman.)
Summary
'Hemorragia', 'sangramiento', and 'sangrado' all refer to the loss of blood but differ in their severity and usage. 'Hemorragia' implies severe internal or external bleeding, 'sangramiento' is a neutral term for any kind of bleeding, and 'sangrado' frequently denotes minor bleedings.