Cause

The causes and factors which trigger primary myelofibrosis are still unknown.

Primary Myelofibrosis has different stages with varying symptoms. However, there are no leading symptoms which would be typical for this disorders. Symptoms can range from none at all to severe. The typical blood count changes also depend on the stage of the disease.

Symptoms

The symptoms of the disease are caused by a change in the blood count (most common is an increase in the thrombocyte count and/or anemia) and are very unspecific, ranging from tiredness, lethargy and bloodclotting to an increased susceptibility to infections.

As the disease progresses, the liver and spleen begin to take over the production of blood to the point that the organs start swelling, leading to splenomegaly and/or hepatomegaly. Besides abdominal swelling, other symptoms such as digestive disorders (diarrhea and constipation) heartburn, and indigestion triggered by fatty foods may also appear. Blood count changes and the blood flow characteristics can also cause further complications such as the building of blood clots in both small and large blood vessels.

The disease's progress can be measured by the extent and progression of the bone marrow fibrosis (displacement of regular hematopoietic cells by tissue).