The hemoglobin content of their blood is only about _______ the normal value of 15 to 16 g/100 ml, because sickled cells are very fragile and rupture easily; this results in anemia. An even more serious consequence is that capillaries become blocked by the long, abnormally shaped cells, causing severe pain and interfering with normal organ function—a major factor in the early death of many people with the disease.