Myelodysplastic Syndrome: When the Bone Marrow Factory Gets a Bit Disorganised

A patient-friendly guide from Dr Ivo Andrejco, Consultant Haematologist

First things first: what on earth is MDS?

Myelodysplastic syndrome, or MDS, is a condition where the bone marrow does not make blood cells properly.

The bone marrow is the soft, spongy tissue inside some of your bones. Its job is to make blood cells every day. It is a bit like a very busy factory — usually reliable, usually quiet, and usually not asking for attention.

In MDS, the factory is still open, the lights are on, and the workers are trying their best — but the production line has become disorganised. Some blood cells are made poorly, some do not mature properly, and some never make it out of the factory at all.

So even though the bone marrow may be working hard, the blood counts in the bloodstream can be low.

Fig. 1 Bone marrow as a blood cell factory producing red cells, white cells and platelets.

What blood cells are affected?

Your bone marrow normally makes three main types of blood cells:

1. Red blood cells — the oxygen delivery vans

Red blood cells carry oxygen around the body. If they are low, this is called anaemia.

Anaemia can cause:

This is often the most common problem in MDS.

2. White blood cells — the infection security team

White blood cells help fight infection. In MDS, some patients have low white cells, especially a type called neutrophils.

This may increase the risk of infections, although not everyone with MDS gets frequent infections.

3. Platelets — the tiny repair crew

Platelets are small, but they take their job very seriously. When they are missing, the body notices.