What Is Clonal Hematopoiesis (CHIP)? A Blood Signal That Links Aging, Heart Risk, and Blood Cancer
Clonal hematopoiesis is an age-related change in blood stem cells. It is a measurable signal associated with higher cardiovascular and blood-cancer risk, but it is not a diagnosis and not a guideline-endorsed screening test.
Medically reviewed by Rhonda Collins, FNP-C | Mito Health on August 27, 2026.
Clonal hematopoiesis (CH) is an age-related process in which a single blood-forming stem cell picks up a mutation that gives it a slight growth advantage, so it slowly produces a larger and larger share of your blood cells. When one of these clones reaches a measurable size and carries a cancer-associated mutation, the finding is often called CHIP, short for clonal hematopoiesis of indeterminate potential. It is common with age, it is usually silent, and it has been linked in observational studies to a higher risk of heart attack, stroke, and blood cancer. It is important to be precise here: clonal hematopoiesis is a promising, measurable, age-associated signal with strong disease associations, not a guideline-endorsed population screening test. The associations come from observational cohorts, and association does not prove causation. Clonal hematopoiesis is not a diagnosis, and any result should be interpreted by a clinician in the context of your full history.
What is clonal hematopoiesis, and what does CHIP mean?
Your bone marrow constantly makes new blood cells from hematopoietic (blood-forming) stem cells. Over a lifetime, those stem cells accumulate random mutations. Most mutations do nothing. Once in a while, a mutation lands in a gene that gives the cell a competitive edge, and the cell begins to expand a population, or clone, of blood cells that all carry the same mutation. That expansion is clonal hematopoiesis.
Researchers describe it as an age-related and lifestyle-related inflammatory process that becomes more common with each decade past 40, and it is seen across populations independent of ancestry (Jaiswal S and Ebert BL, Science 2019;366:eaan4673). The same review makes the point that matters most for prevention: the very clones long studied because they can precede blood cancers are also associated with cardiovascular disease.
CHIP is a narrower label. It refers to clonal hematopoiesis where the mutation sits in a gene associated with blood cancers and the clone is large enough to measure, but the person has normal blood counts and no diagnosed blood disorder. In other words, CHIP describes a measurable clone without disease, which is exactly why it is treated as a risk signal rather than a diagnosis.
Why does clonal hematopoiesis matter for both heart disease and blood cancer?
Most risk markers point at one organ system. Clonal hematopoiesis is unusual because a single finding bridges two very different outcomes. The mutated immune cells that a clone produces appear to behave differently, and one proposed mechanism is that they promote inflammation inside blood-vessel walls, which is central to atherosclerosis (Jaiswal S and Ebert BL, Science 2019;366:eaan4673). At the same time, because the founding mutation often sits in a gene involved in blood-cell development, a growing clone can be an early step on the path toward a hematologic (blood) cancer.
This dual link is what makes clonal hematopoiesis interesting for longevity and prevention. It is a window on two of the outcomes that most shorten healthy lifespan, cardiovascular disease and cancer, from a single blood draw. It is worth restating the ceiling on that claim: these are associations observed in populations, they do not forecast an individual’s future with certainty, and having a clone does not mean disease is inevitable.
How large are the risk associations?
The foundational studies reported sizeable associations, but they came from different populations and different study designs, so the numbers are not interchangeable. Hazard ratios (HR) describe the relative rate of an outcome over time compared with people without the clone. The odds ratio (OR) below comes from case-control studies, which compare people who already had an event against those who did not. One row describes only carriers of a specific mutation, JAK2 V617F, rather than everyone with clonal hematopoiesis.
Outcome | Who the estimate describes | Association | 95% confidence interval |
|---|---|---|---|
Coronary heart disease | CH carriers | ~1.9x (HR 1.9) | 1.4 to 2.7 |
Early-onset heart attack (age 50 or under) | CH carriers | ~4x (OR 4.0) | 2.4 to 6.7 |
Coronary heart disease | Carriers of the JAK2 V617F mutation only | ~12x (HR 12.0) | 3.8 to 38.4 |
Ischemic stroke | CH carriers | ~2.6x (HR 2.6) | 1.4 to 4.8 |
Blood cancer (hematologic malignancy) | CH carriers | ~12.9x (HR 12.9) | 5.8 to 28.7 |
Blood cancer (hematologic malignancy) | CH carriers with VAF 10% or higher | ~49x (HR 49) | 21 to 120 |
Sources: coronary heart disease, early-onset heart attack, and the JAK2-specific estimate from Jaiswal S et al., New England Journal of Medicine 2017;377:111. Ischemic stroke and the VAF 10% or higher blood-cancer estimate from Jaiswal S et al., New England Journal of Medicine 2014;371:2488. Blood cancer in CH carriers from Genovese G et al., New England Journal of Medicine 2014;371:2477. These are observational associations, not causal effects, and confidence intervals are wide.
Read those numbers with their confidence intervals, not as fixed multipliers. The 12x figure sounds dramatic, but it applies only to carriers of the JAK2 V617F mutation, a small minority of people with clonal hematopoiesis, and its confidence interval runs from roughly 3.8 to 38.4, which tells you the true value is uncertain. For CH carriers generally the coronary heart disease association is closer to 1.9x. The associations were also concentrated in larger clones. Small clones carry weaker or unclear associations.
There is an important nuance about age. Detectable somatic mutations are rare before 40 and become steadily more common afterward, yet the risk signal is not uniform across the lifespan. In adults aged 80 and older, one population study found that the presence of clonal hematopoiesis was not associated with higher mortality (van Zeventer IA et al., Blood Advances 2021;5(8):2115). Context changes what a clone means.
Who is clonal hematopoiesis more common in?
Clonal hematopoiesis is fundamentally age-linked, so prevalence climbs through midlife and beyond. Beyond age, it is reported more often in several groups (Jakubek YA et al., Translational Research 2023;255:171):
- Healthy adults roughly 40 to 80, with prevalence rising each decade.
- Cancer survivors who were treated with chemotherapy or radiation.
- People with a history of atherosclerotic disease, such as coronary artery disease or ischemic stroke, or with cardiovascular risk factors including family history, high blood pressure, and high cholesterol.
Being in one of these groups does not mean you have a clone, and many people with a clone never develop the associated diseases. These patterns describe where the signal is more likely to be found, not a verdict about any individual.
What genes does a clonal hematopoiesis test look at?
A CH sequencing test reads a targeted set of genes that recur in clonal hematopoiesis and myeloid blood conditions. Mito offers CardioHemeRISK, a prescription-only sequencing test that examines 15 of these genes: ASXL1, CALR, DNMT3A, FLT3, IDH1, IDH2, JAK2, MPL, PPM1D, RUNX1, SF3B1, SRSF2, TET2, TP53, and U2AF1. Some of these, including JAK2 V617F, CALR, MPL, IDH1, IDH2, and FLT3, are flagged as myeloid-significant, meaning they carry particular weight when interpreting blood-cancer risk.
A CH panel is not the same as an inherited-risk test. These are somatic mutations, acquired by blood cells during life, not germline mutations you were born with and can pass on. CardioHemeRISK does not assess inherited genetic risk, and it does not include every gene ever associated with these outcomes, so some at-risk people will have no detected clone.
What does a CardioHemeRISK score tell you?
Rather than handing you a raw list of mutations, CardioHemeRISK summarizes the finding as a single CardioHemeRISK score. The score is built from the CH variant with the highest detected VAF plus the risk conferred by the specific variant or variants present, and it maps to a category with a suggested re-test interval. The bands below are illustrative. Your own report gives the exact genes, score, category, and interval.
CardioHemeRISK score | Category | Typical re-test interval |
|---|---|---|
0.0 | Not Detected | Per your clinician |
>0.0 to <0.5 | Trace | Repeat in about 3 years |
0.5 to <2.0 | Slightly Elevated | Repeat in about 3 years |
2.0 to <10.0 | Moderately Elevated | Repeat annually |
≥10.0 | Highly Elevated | Repeat annually |
CardioHemeRISK score bands, categories, and suggested re-test intervals, adapted from the CardioHemeRISK report. Categories are anchored to hazard-ratio-based risk tiers, and this graphic is illustrative: the specific genes and interval come from your individual report. If myeloid-significant mutations are detected alongside a Slightly Elevated or Moderately Elevated score, a clinician may recommend re-evaluation at 1-to-3-year intervals.
The score is designed to make an abstract finding actionable, but the action is a conversation with a clinician, not a self-directed decision. A higher band generally means a larger clone and a shorter suggested interval for rechecking, so the test can be repeated over time to see whether a clone is stable or growing.
Is clonal hematopoiesis testing recommended for everyone?
No. This is the single most important framing in the whole topic. Clonal hematopoiesis is a real, measurable signal with strong associations, but no major guideline recommends CH sequencing as a population screening test the way mammography or colonoscopy are recommended. It belongs to comprehensive, individualized risk assessment for the right person, not to a blanket recommendation for everyone.
Some experts argue the case for wider use in older adults. In his book Super Agers, the cardiologist and researcher Dr. Eric Topol has said he believes clonal hematopoiesis should be routinely assessed in older adults as part of a comprehensive risk assessment. That is a notable expert view, and it is still one view rather than a guideline mandate. It is best read as a reason to discuss CH testing within an individualized plan, especially if you are older or already carry cardiovascular or cancer-treatment history, not as a directive that every adult should test.
There is also an active research frontier worth naming carefully. Exploratory studies have shown that anti-inflammatory drugs can reduce clonal hematopoiesis levels, but that is an early research finding, not an approved treatment, and nothing here should be read as a treatment recommendation.
How Mito fits clonal hematopoiesis into the bigger picture
A CH score is most useful next to the rest of your health data, not alone. That is where Mito’s model helps. You can order CardioHemeRISK ($899.64, or $642.60 for Mito members, HSA/FSA eligible) through Mito’s telehealth partner, who reviews your request and orders the test if it is appropriate for you. Sample collection is done by mobile phlebotomy at your home or workplace, so there is no lab visit to schedule.
Because Mito already houses the rest of your bloodwork, a CH finding does not sit in isolation. You can read it alongside your cardiovascular markers, inflammation, and metabolic health, ask follow-up questions through Mito Concierge, and book a 1:1 consultation with your care team to decide what, if anything, the score should change. That is the right home for a signal like this: interpreted in context, by a clinician, as one input among many.
If you want to understand your broader picture first, the Cancer Risk Profile quiz is a low-commitment starting point.
Frequently asked questions
Is clonal hematopoiesis a type of cancer? No. Clonal hematopoiesis and CHIP describe a measurable clone of blood cells without a diagnosed blood disorder. It is associated with a higher risk of blood cancer in observational studies, but most people with a clone never develop cancer.
Does everyone develop clonal hematopoiesis with age? It becomes more common each decade past 40 and is common in older adults, but not universal. Detectable clones are rare before 40 (Jaiswal S and Ebert BL, Science 2019).
Is a bigger clone worse? The strongest disease associations were seen with larger clones, at a variant allele frequency above 10 percent (Jaiswal S et al., NEJM 2017). Smaller clones carry weaker or less certain associations, which is one reason results are interpreted by a clinician.
Can I lower my clonal hematopoiesis? Exploratory research has shown anti-inflammatory drugs can reduce CH levels, but this is early research, not an approved treatment. There is no established therapy to eliminate a clone, so the focus is on managing overall cardiovascular and cancer risk.
Is this the same as a genetic test I would get from a cheek swab? No. This measures somatic mutations acquired by blood cells during life, not inherited germline genes. It does not assess inherited risk and is not a substitute for genetic counseling.
Related reading
- Does a Standard Blood Test Detect CHIP? CBC vs. CH Sequencing
- How to Get Tested for Clonal Hematopoiesis (CHIP) and What It Costs
- Clonal Hematopoiesis (CHIP): The Complete Guide
- Clonal Hematopoiesis and Heart Disease
Medical disclaimer
This article is for informational purposes only. It does not diagnose any condition and does not replace medical care. Clonal hematopoiesis testing, including CardioHemeRISK, is a prescription-only laboratory-developed test that is not FDA-cleared. It is a screening signal, not a diagnosis. The risk figures cited here are observational associations, and association does not prove causation. A negative or low result does not mean you are risk-free, and an elevated result needs to be interpreted and followed up by a qualified clinician in the context of your symptoms, history, examination, and other testing.
