4. Shortness of Breath
With a lower amount of red blood cells in the body, it should come as no real surprise that you may find it difficult to exert yourself.
The thing to recognize here is that EPO is something that is used by a number of athletes in order to get the edge on the competition (it is banned by most organizations but its use persists!). The increase in EPO gives them so much extra energy and endurance that they are able to complete races much more quickly than they would otherwise be able to.
But having low levels of EPO can similarly cause the precise opposite effect and essentially make simple tasks like climbing the stairs feel like a massive workout!
There are other reasons for this shortness of breath too. One is that fluids can gather on the lungs (more on why this happens in a moment), thereby making the patient struggle to breathe.