Intravascular heamolysis occurs in
Paroxysmal noctural hemoglobunuria (PNH) is the only hemolytic anemia caused by an acquired intrinsic defect in the cell membrane. It is associated with intravascular hemolysis. Rest all conditions causes extravascular heamolysis.
Hereditory spherocytosis
Antoimmune haemolytic anemia
Paroxysmal nocturnal hemoglobinuria
Thalassemia