Myelofibrosis usually develops slowly. In its very early stages, many people don't experience signs or symptoms. As disruption of normal blood cell production increases, signs and symptoms may include:  Feeling tired, weak or short of breath, usually because of anemia Pain or fullness below your ribs on the left side, due to an enlarged spleen Easy bruising Easy bleeding Excessive sweating during sleep (night sweats) Fever Bone pain 
myelofibrosis develops slowly  early stages  people don't experience signs symptoms  disruption normal blood cell production increases  signs symptoms may include:  feeling tired  weak short breath  anemia pain fullness ribs left side  due enlarged spleen easy bruising easy bleeding excessive sweating sleep (night sweats) fever bone pain 
myelofibrosis