Infection: a shortage of white blood cells (neutropenia), heightens your risk of infection. It is quite common for people with severe bone marrow failure to die from an infection, for example a chest infection. If the infection gets into your bloodstream (sepsis), you could lose consciousness.
A shortage of oxygen to your organs: a shortage of red blood cells (anaemia) can stop your organs from getting enough oxygen to function properly. This can cause shortness of breath, weakness and fatigue.
Bleeding: a shortage of platelets (thrombocytopenia) increases your risk of bleeding and bruising. Bleeding can be internal (inside your body, such as in your gut), as well as external. Internal bleeding can cause serious complications and lead to death. Thrombocytopenia can also increase your risk of bleeding in the brain. This can cause a stroke (a serious medical condition that happens when the blood supply to your brain is cut off).