Why is fatigue common in people with MPNs?

Fatigue is common in patients with myeloproliferative neoplasms and can be due to a number of reasons. The excessive production of blood cells and inflammatory signals can put the body in a constant state of tiredness. The fatigue could also be caused by another organ system that is being affected by the MPN, such as an enlarged spleen. Additionally, some treatment methods could cause tiredness and medication doses may need to be altered in order to counteract the excess fatigue.