# Symptoms and phases of myelodysplastic syndrome
Myelodysplastic syndrome (MDS) progresses in stages that differ per patient. One person has little trouble for years, another develops serious symptoms more quickly. This document describes the main phases and what typically comes with them.
Very early phase (CCUS/ICUS)
In this phase, abnormalities are visible in the bone marrow (under the microscope or via genetic testing), but usually no clear disease symptoms yet. Many patients feel healthy.
**Symptoms:**
- Usually no complaints or very subtle fatigue
- Sometimes discovered during incidental blood tests
**What it means for daily life:**
- Patients often notice nothing. Work, household chores and leisure continue normally.
- Psychologically, certainty about the diagnosis can be burdensome.
**Figures about this phase: **
Patients in this very early phase (CCUS = clonal cytopenia of undetermined significance, or ICUS = idiopathic cytopenia of undetermined significance) have a low risk of progression. On average, it takes years for true MDS features to develop; many people never experience this. Exact progression rates vary widely and depend on genetic findings. Individual progression is highly dependent on personal factors.
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Low-risk phase (Low-Risk MDS)
This is the most common form of MDS. The bone marrow produces cells, but not well enough. Blood values are usually low, but not dramatic. The condition grows slowly.
**Symptoms:**
- **Fatigue** (most common): occurs because the body does not have enough red blood cells
- **Shortness of breath** on exertion: also a result of anemia
- **Paleness** of skin and lips
- **More frequent bruising and bleeding**: because the number of platelets is low; for example nosebleeds, gum bleeding or menstrual bleeding that lasts longer
- **Infections** that occur somewhat more frequently: white blood cells function poorly
- In some, **weakened bones** (osteoporosis) or **gout complaints** (due to high uric acid levels)
- **Weight gain** sometimes due to medications or changes in diet
**What it means for daily life:**
- Many patients can still work, but feel exhausted in the afternoon
- Climbing stairs can become difficult
- Sports and heavy household tasks are limited
- Regular blood transfusions (usually 1–2 per month) take up time
- Infections may require time off work
- Social activities are sometimes postponed due to fatigue
**Figures about this phase: **
The low-risk phase lasts on average **several years**. In large population studies, 5-year survival rates range around **50–70%**, but this varies widely and depends on age, type of MDS, gender and other factors. These figures say nothing about an individual prognosis — someone may live much longer or shorter than these averages.
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Intermediate phase (Int-1 and Int-2 risk)
In this phase, the number of immature cells in the bone marrow increases. The disease process progresses faster than in low-risk MDS. The risk of transformation to acute leukemia increases.
**Symptoms:**
- All symptoms of low-risk MDS, but usually **more severe**:
- **Severe fatigue**: many patients feel tired almost daily
- **Recurring or worsening anemia**: more headaches, dizziness
- **More frequent bruising and bleeding**: gum bleeding, nosebleeds become more common
- **Infections** occur more frequently; some develop fever, flu-like symptoms
- **Sometimes mild fever** without a clear cause
- **Weakness**: doing groceries or taking a walk becomes difficult
- Some also feel **stitches in the bone marrow** (especially at sternum or ribs)
**What it means for daily life:**
- Working becomes more difficult; many need flexible work or fewer working hours
- More hospital visits for check-ups and possible treatment
- Blood transfusions needed more frequently (possibly weekly)
- Social life limited by fatigue and precautions against infections
- Fear of progression to leukemia is more prominent
**Figures about this phase: **
Patients in intermediate phases (Int-1 and Int-2) have a **median survival of approximately 1.5–4 years**, depending on which subcategory and other prognostic factors. These are averages across large groups; individual courses vary considerably. The risk of transformation to acute leukemia is several percent per year in these phases, but is highly dependent on the exact genotype and the amount of immature cells.
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High-risk phase (High-Risk MDS)
This is the most severe stage of MDS. The bone marrow is severely disrupted, with many immature blood cells. The chance of conversion to acute leukemia is significant.
**Symptoms:**
- All previous symptoms, now usually **severe**:
- **Extreme fatigue**: patients can barely manage
- **Severe anemia**: very dizzy, little energy
- **Regular bleeding**: severe nosebleeds, blood in stool or urine, severe gum bleeding
- **Very low immunity**: infections can become very serious rapidly (pneumonia, sepsis)
- **High fever** and flu-like symptoms
- **Swollen lymph nodes** or **enlarged spleen/liver** (in some cases)
- **Bone pain** or **stabbing sensations in the bone marrow** more often
- Sometimes **skin abnormalities** (red spots, especially on face and torso)
**What it means for daily life:**
- Work is usually no longer possible
- Almost daily patients feel sick
- Hospital admissions for infections or transfusions become more frequent
- Highly dependent on help from family or home care
- Planned treatment (such as chemotherapy or stem cell transplantation) demands much energy
- Psychologically taxing: the feeling that the disease is accelerating
**Figures about this phase: **
Patients with high-risk MDS have a **median survival of several months to approximately 1 year** without treatment aimed at preventing transformation. With treatment (for example hypomethylating agents such as azacitidine or decitabine) this can be considerably longer. Recent data (2025–2026) are examining how well maintenance transplantation with venetoclax works after stem cell transplantation, which can prolong survival. These are, however, population figures; individual outcomes can differ greatly and depend on age, genetic factors, whether someone can tolerate stem cell transplantation, and responsiveness to treatment.
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Transformation to acute myeloid leukemia (AML)
When MDS transforms into acute leukemia, everything changes suddenly. The bone marrow is now completely disrupted and produces almost only immature cells.
**Symptoms:**
- **Extremely severe fatigue** and weakness
- **Severe anemia**: fainting, dizzy even at rest
- **Massive bleeding**: from nose, mouth, urine, stool; sometimes bleeding spots on skin (petechiae)
- **Very frequent and severe infections**: often life-threatening pneumonias or sepsis
- **High fever** (39°C+), sometimes with chills
- **Pain**: bone pain, pain in lower or upper abdomen from enlarged spleen/liver
- **Headache** and sometimes confusion (due to leukemic cells in the brain)
- **Rapid deterioration**: within days to weeks
**What it means for daily life:**
- Patients become very acutely ill; hospitalization is almost always necessary
- Intensive treatment (aggressive chemotherapy or combination therapies)
- Possible admission to intensive care
- Psychologically taxing and physically very demanding
**Figures about this phase: **
Without treatment, the median survival of AML in general is **several weeks to months**. With intensive chemotherapy, some patients can achieve remission and live longer; this, however, depends greatly on age, overall health and whether stem cell transplantation is possible. Survival figures for post-transformation are less favorable than for primary AML, and great variability is large.
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When to contact your healthcare provider?
Contact your doctor or the hospital without delay if you experience one or more of the following:
- **Sudden severe bleeding** (much blood in urine or stool, nosebleed that doesn't stop)
- **High fever (>38.5°C)** and you feel really sick (especially with low white blood cell counts)
- **Severe shortness of breath** or chest pain
- **Severe confusion or headache** with fever
- **Petechiae** (many bruises in a short time) without reason
- **Severe weakness**: you can no longer get up or are very disoriented
- **Prolonged vomiting** or abdominal pain
It is also wise to maintain regular contact with your doctor in case of less dramatic symptoms: if your fatigue gets worse, infections become more frequent, or you feel yourself deteriorating.
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_This information never replaces a doctor's judgment. Always discuss your situation with your own healthcare provider._