Myelodysplastic Syndrome

What is myelodysplastic syndrome?

Myelodysplastic syndrome, often shortened to MDS, is a group of conditions in which the bone marrow — the soft, spongy tissue inside the bones that makes blood cells — does not produce healthy blood cells the way it should. In myelodysplastic syndrome, many of the blood cells that the marrow makes are abnormally formed (a feature doctors call dysplasia) and die early, either in the marrow itself or shortly after entering the bloodstream. The result is a shortage of one or more types of mature, working blood cells.

To understand what is myelodysplastic syndrome, it helps to know the three main types of blood cells and what they do. Red blood cells carry oxygen around the body; when they are low, the condition is called anemia. White blood cells fight infection; a shortage is called neutropenia. Platelets help blood clot; a shortage is called thrombocytopenia. In myelodysplastic syndrome, any or all of these cell lines can be affected, and the specific pattern helps doctors classify the disease into subtypes.

Myelodysplastic syndrome is considered a form of blood cancer, although it behaves very differently from most cancers. It usually develops slowly, and in some people it remains mild and stable for years. In others, it progresses more quickly, and in a portion of patients it can transform over time into acute myeloid leukemia (AML), a faster-growing cancer of the blood and bone marrow. Because of this range of behavior, doctors often describe myelodysplastic syndrome as a spectrum, from lower-risk to higher-risk disease.

MDS most often affects older adults, typically people over the age of 60, and it is somewhat more common in men than in women. It can occur in younger people, but this is less usual and is sometimes linked to previous cancer treatment or inherited conditions. The general code used for unspecified myelodysplastic syndrome in medical records is ICD-10 D46.9.

Symptoms of myelodysplastic syndrome

Myelodysplastic syndrome symptoms develop because the body does not have enough healthy blood cells. In the early stages, many people have no symptoms at all, and the condition is discovered by chance when a routine blood test shows low blood counts. When symptoms do appear, they usually reflect which type of blood cell is most affected.

Common myelodysplastic syndrome symptoms include:

• Fatigue and weakness — the most frequent complaint, caused by anemia (too few red blood cells carrying oxygen).
• Shortness of breath, especially with activity such as climbing stairs.
• Pale skin, which may be noticed by family members before the patient.
• Frequent or unusually severe infections, caused by low or poorly functioning white blood cells.
• Easy bruising or bleeding, such as nosebleeds, bleeding gums, or bruises that appear without a clear cause, due to low platelets.
• Tiny red or purple spots under the skin (called petechiae), also related to low platelets.
• Dizziness or lightheadedness, and sometimes chest discomfort in people with existing heart disease, because anemia forces the heart to work harder.

How symptoms present often depends on the subtype and stage of the disease. In lower-risk myelodysplastic syndrome, anemia is frequently the only problem, and it may be mild enough that the person simply feels more tired than usual. In higher-risk disease, several cell lines are usually affected at once, so fatigue, infections, and bleeding problems may occur together and worsen over months rather than years. A rapid increase in symptoms — for example, new fevers, spreading bruises, or severe exhaustion over a short period — can sometimes signal that the disease is progressing, and it should always be discussed with a doctor promptly.

It is important to remember that all of these symptoms are common and have many possible causes, most of which are not myelodysplastic syndrome. Only proper testing can determine the reason for low blood counts.

Causes and risk factors

In most people, myelodysplastic syndrome causes cannot be identified with certainty. The disease begins when the DNA (the genetic instructions inside cells) of a blood-forming stem cell in the bone marrow becomes damaged. This damaged cell then multiplies and gradually crowds out normal blood production. Why these genetic changes happen in a particular person is usually unknown; in most cases MDS arises without any clear trigger, and doctors then call it primary or de novo myelodysplastic syndrome.

However, several factors are known to increase the risk of developing MDS:

• Older age. The risk rises steadily with age, and most people are diagnosed after 60. Aging naturally allows genetic errors to accumulate in bone marrow cells.
• Previous cancer treatment. Certain chemotherapy drugs and radiation therapy can damage bone marrow cells. MDS that develops after such treatment is called therapy-related myelodysplastic syndrome and often behaves more aggressively.
• Exposure to certain chemicals. Long-term exposure to benzene (found in some industrial settings) and possibly other solvents or heavy metals has been linked to a higher risk.
• Smoking. Tobacco smoke contains benzene and other substances that can harm bone marrow.
• Male sex. MDS is somewhat more common in men.
• Certain inherited conditions. Rare inherited disorders that affect bone marrow function, such as Fanconi anemia, can increase risk, particularly in younger patients.

Myelodysplastic syndrome is not contagious, and in the great majority of cases it is not passed from parent to child. Having a risk factor does not mean a person will develop the disease, and many people with MDS have no identifiable risk factor at all.

Diagnosis

Myelodysplastic syndrome diagnosis usually begins with a routine blood test that shows unexplained low blood counts. Because many other, more common conditions can lower blood counts — including vitamin B12 or folate deficiency, iron deficiency, thyroid problems, alcohol use, medication side effects, and other bone marrow diseases — doctors must carefully rule these out before confirming MDS.

The main tests used are:

• Complete blood count (CBC). This measures the numbers of red blood cells, white blood cells, and platelets. In MDS, one or more of these counts is typically low.
• Peripheral blood smear. A drop of blood is examined under a microscope. In MDS, blood cells often look abnormal in size or shape.
• Blood chemistry and vitamin tests. These help exclude other causes of low counts, such as nutritional deficiencies or kidney and liver problems.
• Bone marrow aspiration and biopsy. This is the key test for confirming myelodysplastic syndrome. Using local anesthesia, a doctor removes a small sample of liquid marrow (aspiration) and a tiny core of bone with marrow inside (biopsy), usually from the back of the hip bone. A specialist then examines the samples under a microscope, looking for dysplastic (abnormally formed) cells and counting immature cells called blasts. The proportion of blasts helps distinguish MDS from acute leukemia and helps determine how advanced the disease is.
• Cytogenetic and molecular testing. The marrow sample is also tested for chromosome changes and specific gene mutations. These findings are important because they influence both the risk category and, in some cases, the choice of treatment.

Once the diagnosis is confirmed, doctors use scoring systems — most commonly versions of the International Prognostic Scoring System (IPSS) — to classify the disease as lower-risk or higher-risk. This score combines blood counts, the percentage of blasts in the marrow, and genetic findings. It does not predict any individual’s future with certainty, but it guides how closely a person should be monitored and which treatments are most appropriate. Imaging scans are not usually needed to diagnose MDS itself, because the disease lives in the bone marrow and blood rather than forming a tumor that can be seen on a scan.

Treatment options

Myelodysplastic syndrome treatment depends on the risk category of the disease, the symptoms it is causing, the person’s age and overall health, and their own preferences. Not everyone needs treatment right away, and the goals of treatment differ from person to person: for some, the aim is to relieve symptoms and improve quality of life; for others, it is to slow the disease or attempt a cure. Care for this condition is typically coordinated by a hematology department, where specialists in blood disorders manage diagnosis, treatment, and long-term follow-up; at Acibadem, patients with this diagnosis are managed within this specialty. More detail about how the condition is managed can be found on the myelodysplastic syndrome treatment page.

Watchful waiting (active monitoring)

For people with lower-risk MDS who have mild blood count changes and few or no symptoms, doctors often recommend regular monitoring rather than immediate treatment. This involves periodic blood tests and check-ups so that any change in the disease is detected early. Starting treatment before it is needed does not usually improve outcomes and can expose people to unnecessary side effects.

Supportive care

Supportive care aims to relieve the effects of low blood counts rather than to change the disease itself. It may include:

• Blood transfusions of red blood cells for significant anemia, or platelets for bleeding problems.
• Growth factors, which are medications that stimulate the bone marrow to make more of a particular blood cell — for example, erythropoiesis-stimulating agents for red blood cells.
• Antibiotics to treat infections promptly, and sometimes preventive measures against infection.
• Iron chelation therapy, a medication treatment that removes excess iron from the body, which may be considered in people who receive many red blood cell transfusions over time, because repeated transfusions can lead to iron buildup in organs.

Disease-modifying medications

Several classes of medication can act on the disease itself:

• Hypomethylating agents (such as azacitidine and decitabine) are drugs that affect how genes are switched on and off in abnormal marrow cells. They are commonly used in higher-risk MDS and can improve blood counts and slow progression in many patients, although responses vary and are not permanent in most cases.
• Lenalidomide is an immunomodulatory drug that can be particularly effective in a subtype of MDS associated with a specific chromosome change called deletion 5q.
• Immunosuppressive therapy may help selected patients whose disease appears to involve the immune system attacking the bone marrow.
• Other targeted and newer agents may be options for specific genetic subtypes; your doctor may also discuss clinical trials, which study new treatments under careful supervision.

Chemotherapy

Intensive chemotherapy, similar to that used for acute myeloid leukemia, is sometimes used for higher-risk MDS, particularly in fitter patients or as preparation for a stem cell transplant. It carries significant side effects and is not suitable for everyone.

Stem cell transplantation

An allogeneic stem cell transplant — replacing the patient’s diseased bone marrow with healthy blood-forming stem cells from a donor — is currently the only treatment with the potential to cure myelodysplastic syndrome. However, it is a demanding procedure with serious risks, including infection and a complication called graft-versus-host disease, in which donor immune cells attack the patient’s tissues. Because of these risks, transplant is generally considered for younger or fitter patients with higher-risk disease, and the decision requires careful, individualized assessment. Surgery in the traditional sense plays no role in treating MDS, since the disease affects the bone marrow throughout the body rather than a single removable site.

Living with myelodysplastic syndrome and outlook

The outlook for myelodysplastic syndrome varies enormously from person to person. Some people with lower-risk disease live for many years with few symptoms and little or no treatment beyond monitoring. Others with higher-risk disease face a more difficult course, including the possibility of progression to acute myeloid leukemia. Risk scores give doctors a general framework, but they are statistical tools based on groups of patients — they cannot tell any individual exactly what will happen. Honest, ongoing conversations with the treating team are the best way to understand what a particular diagnosis means.

Day to day, many people with MDS find the following helpful:

• Attending all scheduled blood tests and appointments, since blood counts guide every decision.
• Reducing infection risk through hand hygiene, avoiding close contact with people who are ill, and keeping vaccinations up to date as advised by the care team.
• Reporting fevers promptly. In a person with low white blood cells, a fever can become serious quickly and should never be ignored.
• Pacing activity to manage fatigue, while staying as physically active as symptoms allow.
• Eating a balanced diet and discussing any supplements with the doctor before taking them.
• Avoiding smoking and limiting alcohol, both of which can affect bone marrow and general health.
• Seeking emotional support. A chronic blood cancer diagnosis is stressful; counseling, patient support groups, and open conversations with family can make a real difference.

People taking blood-thinning medications or drugs that affect platelets should review them with their doctor, since low platelet counts can increase bleeding risk. It is also wise to tell dentists and other healthcare providers about the diagnosis before any procedure.

Frequently asked questions

What is myelodysplastic syndrome in simple terms?

In simple terms, myelodysplastic syndrome is a bone marrow disorder in which the “blood cell factory” inside the bones produces faulty cells. Because many of these cells do not survive or work properly, the person ends up with too few healthy red blood cells, white blood cells, or platelets. It is classified as a form of blood cancer, but it often develops slowly, and its severity ranges widely from mild to serious.

Is myelodysplastic syndrome a type of leukemia?

Myelodysplastic syndrome is related to leukemia but is not the same thing. Both begin in blood-forming cells of the bone marrow. In MDS, the marrow still produces cells, but many are defective; in acute leukemia, immature cells multiply rapidly and crowd out normal blood production. In some patients, MDS progresses over time into acute myeloid leukemia, which is why doctors monitor the disease closely.

Can myelodysplastic syndrome be cured?

At present, the only treatment with the potential to cure myelodysplastic syndrome is an allogeneic stem cell transplant, in which diseased bone marrow is replaced with healthy donor cells. This procedure carries significant risks and is suitable mainly for selected patients, often those who are younger or fitter with higher-risk disease. For many people, treatment focuses instead on controlling the disease, improving blood counts, and maintaining quality of life, often for extended periods.

How serious is myelodysplastic syndrome?

The seriousness varies greatly. Doctors use risk scores that combine blood counts, the percentage of immature cells in the marrow, and genetic findings to classify the disease as lower-risk or higher-risk. Lower-risk MDS may remain stable for years and cause few problems, while higher-risk MDS tends to progress faster and has a greater chance of transforming into acute leukemia. Only the treating team, with full test results, can give a realistic picture for an individual patient.

What are the first symptoms of myelodysplastic syndrome?

The earliest and most common symptom is fatigue caused by anemia — feeling unusually tired, weak, or short of breath during everyday activities. Some people also notice pale skin, frequent infections, or easy bruising and bleeding. Importantly, many people have no symptoms at first, and the condition is found through a routine blood test. Because these symptoms are common to many conditions, they need proper medical evaluation rather than self-diagnosis.

Does myelodysplastic syndrome always need treatment right away?

No. Many people with lower-risk myelodysplastic syndrome and mild blood count changes are managed with active monitoring, meaning regular blood tests and check-ups without immediate treatment. Treatment is generally started when the disease causes meaningful symptoms, when blood counts fall to levels that create risk, or when tests show the disease is progressing. This approach avoids unnecessary side effects while keeping a close watch on the condition.

Can lifestyle changes help with myelodysplastic syndrome?

Lifestyle changes cannot cure MDS, but they can support overall health and reduce complications. Not smoking, practicing good hand hygiene, staying up to date with recommended vaccinations, eating a balanced diet, and staying moderately active as energy allows are all sensible steps. People with low platelets are usually advised to be careful with activities that carry a high risk of injury, and anyone with MDS should report fevers or unusual bleeding to their doctor without delay.

When to see a doctor

Anyone with persistent, unexplained fatigue, breathlessness, frequent infections, or easy bruising should see a doctor for a blood test. For people already diagnosed with myelodysplastic syndrome, certain warning signs need urgent medical attention because low blood counts can turn minor problems into serious ones quickly.

Seek urgent medical care if you experience:

• Fever (generally 38°C / 100.4°F or higher), chills, or shaking — in a person with low white blood cells, this may signal a serious infection.
• Bleeding that will not stop, including nosebleeds lasting more than a few minutes, blood in the urine or stool, or coughing or vomiting blood.
• A sudden increase in bruising or a rash of tiny red or purple spots under the skin.
• Severe shortness of breath, chest pain, or a racing heartbeat, which can indicate that anemia is straining the heart.
• A sudden severe headache, confusion, or changes in vision, which could suggest bleeding related to very low platelets.
• Extreme weakness, dizziness, or fainting.

If any of these occur, do not wait for the next scheduled appointment — contact your care team or go to the nearest emergency department. Prompt action in these situations can prevent serious complications, and it is always better to have a warning sign checked and reassured than to delay.