Biomarkers are measurable indicators of health that can reveal what’s happening inside your body before symptoms appear.
Key Takeaways:
Biomarkers are measurable indicators of health that can reveal what’s happening inside your body before symptoms appear.
Different types of biomarkers are used for diagnosis, prognosis, predicting treatment response, monitoring progress, and ensuring treatment safety.
Understanding your biomarkers empowers you to take a more proactive role in your health.
Healthcare providers are often able to pinpoint specific diseases, predict how conditions progress, and tell whether a treatment is working. To do this work, the providers aren’t using magic or their own imaginations. Instead, they use measurable clinical data — including biomarker levels — to inform their decisions.
Biomarkers are measurable indicators of a biological state or condition. For instance, low iron levels may suggest iron-deficiency anemia.
The human body is a complex machine, and many different types of biomarkers exist for various purposes, whether to diagnose, assess, or inform. Below, we’ve categorized biomarkers based on their purposes and the data they can provide.
A biomarker — or a biological marker — is like a biological speedometer or dashboard light that comes on to indicate that something requires attention. Just as your car might have a low tire pressure warning, your body produces molecules and cells and experiences physiological changes that signal what’s happening internally. Essentially, biomarkers communicate in a language only your body can speak.
Examples include specific proteins that don’t normally circulate in your bloodstream, a genetic mutation in your DNA, an image from an MRI scan, or even how fast your heart is beating.
What makes these biomarkers meaningful is that they’re measurable and they correlate with a biological process, a disease, or a response to a therapy or treatment.
Learn more in our guide to biomarkers.
Because biomarker levels influence healthcare decisions that affect you directly, it’s essential to understand what they measure and how doctors use different types.
For example, if someone receives a cancer diagnosis, specific biomarkers found on the tumor might guide the treatment plan. If you’re managing a chronic condition like diabetes, regular monitoring of related biomarkers — like blood glucose levels and hemoglobin A1C (HbA1c) — is essential for proper management and preventing complications.
In preventive health, understanding specific biomarkers might help you make lifestyle-related decisions to reduce potential future risks.
Biomarkers provide a snapshot of your internal environment, and they can highlight subtle shifts long before noticeable symptoms appear. For instance, elevated cholesterol levels (a lipid biomarker) won’t cause pain, but they do serve as a warning for increased cardiovascular disease risk.
You can measure many biomarkers via blood draw, whether during your annual wellness exam or ordered specifically to investigate certain symptoms or health concerns you bring up to your provider. Both are important opportunities to gather more data and monitor trends over time.
Let’s take a closer look at the seven main types of biomarkers, including their purposes, when they might be ordered, and what they can tell you about your health.
As the name suggests, diagnostic biomarkers are biological detectives used to identify the presence of a disease or condition. They may function as a “smoking gun” that confirms what a provider suspects based on symptoms you’ve shared.
For example, symptoms like a persistent cough and fever may prompt your provider to evaluate for a possible infection. To determine whether bacteria are responsible, your provider may order a culture that can identify the specific organism. This can result in proper treatment without the need for any guesswork.
A well-known biomarker related to prostate health is prostate-specific antigen (PSA). Elevated PSA levels are not diagnostic for prostate cancer but may prompt further evaluation.
Diagnostic biomarkers provide objective evidence, as opposed to symptoms we experience, which can sometimes be vague. Diagnostic biomarker data provides clarity, helps to differentiate between diseases, and prevents unnecessary treatments that may be ineffective or potentially harmful.
After a provider makes a diagnosis, prognostic biomarkers help predict the likely course of a given condition, its severity, and outcome — independent of treatment.
For example, if two people receive a diagnosis for the same type and stage of cancer, prognostic biomarkers (like a particular gene mutation within the tumor) could provide evidence that one of their cancers may be faster-growing and more aggressive than the other.
In this way, prognostic biomarkers help manage expectations about what to expect with a disease, without taking into account possible treatments. This helps with preparation and managing expectations regarding how the disease is most likely to play out.
Predictive biomarkers help us look toward future treatment options, indicating how a specific person might respond to interventions for a disease. The focus is on personalized medicine.
For example, let’s consider breast cancer: Historically, many people received standard chemotherapy treatment, but with predictive biomarkers like HER2 (human epidermal growth factor receptor 2) status, healthcare professionals can now identify if a patient has a tumor overexpressing HER2.
In this case, that patient is likely to respond well to targeted therapies like trastuzumab (Herceptin), which specifically blocks the HER2 pathway. Oppositely, someone who is HER2-negative would not benefit from this drug and could avoid its side effects.
Another example is melanoma, a form of skin cancer, where the presence of a BRAF mutation predicts a good response to BRAF inhibitor drugs for treatment.
Without these predictive biomarkers, oncologists would have less evidence to guide people to the most effective treatments.
Pharmacodynamic biomarkers, or response biomarkers, measure the effect of the drug on the body and whether it’s producing the desired changes. Essentially, it can reveal whether a treatment is working as intended.
For example, if you’re taking an antihypertensive medication to lower your blood pressure and treat hypertension, a blood pressure reading would be an appropriate response biomarker because it shows whether the drug is effective. And in cancer treatment, if the size of a tumor decreases as shown by an MRI or CT scan, the imaging is the response biomarker to show whether the therapy is working.
Pharmacodynamic biomarkers help ensure a person is receiving enough of a treatment to be effective without opening the risk of excessive side effects, and that the intervention is interacting with its intended target (like a malignant tumor or high blood pressure).
The function of monitoring biomarkers is to track disease progression, disease recurrence, or the long-term effectiveness of a treatment. They help provide ongoing feedback on how the condition is changing or how the treatment is performing.
For example, people with diabetes may use hemoglobin A1C to monitor average blood glucose levels over the past three months. The results can distill how well-controlled the condition is and whether the current treatment may benefit from any adjustment.
Monitoring biomarkers help keep tabs on chronic conditions, reduce the likelihood of relapses, and ensure that the chosen therapeutic interventions continue to be appropriate and effective.
Prostate-specific antigen (PSA) is not diagnostic for prostate cancer, but it is a useful monitoring biomarker. After a prostate cancer diagnosis or treatment, PSA levels are checked regularly to track response and watch for recurrence. PSA trends over time — such as rising levels — can signal whether the condition is stable, progressing, or needs further evaluation. PSA monitoring is always interpreted in context and not used alone to diagnose cancer.
Susceptibility biomarkers focus on the possibility of future health conditions. Providers can analyze the metrics for factors like predisposition, susceptibility, and risk.
For example, BRCA1 and BRCA2 genetic mutations aren’t diagnostic for breast or ovarian cancer, and also don’t predict response to treatment. However, the presence of the mutation(s) can indicate a significantly increased risk of developing these cancers during a person’s lifetime.
Having this information can help individuals advocate for themselves and can also guide providers to make appropriate screening recommendations, as appropriate.
Another example of a risk biomarker is ApoE4, a genetic variant associated with an increased risk of developing Alzheimer’s disease. Just because you have ApoE4 doesn’t mean you’ll get Alzheimer’s, but it does indicate a higher genetic risk.
Safety biomarkers help make sure medical interventions, like drugs, don’t cause unintended harm during treatment. These biomarkers are an essential aspect of drug development and clinical trials, helping to detect and monitor adverse effects or toxicity associated with a drug or environmental exposure.
When you start a new course of medication, your provider might order periodic blood tests to check liver function. For example, elevated levels of liver enzymes like ALT or AST can be safety biomarkers, signaling potential drug-induced liver injury.
Monitoring biomarkers isn’t a one-size-fits-all process. Instead, tracking depends on the specific biomarker, the condition in question, and an individual’s clinical situation.
However, monitoring typically includes these general recommendations and tools:
Blood tests. A simple blood draw can provide information on biomarkers like enzymes, proteins, glucose, cholesterol panels, and even circulating tumor DNA.
Urine tests. A urinalysis (urine analysis) can help detect kidney abnormalities, identify infections, and measure metabolic byproducts of certain drugs.
Imaging. Visual changes captured by MRI, CT scans, and ultrasounds can help providers understand the size of a tumor, the health of an organ, or even changes in your brain that may indicate a progressive disease.
Tissue biopsies. For certain conditions like cancers, tissue samples may be analyzed in a lab to confirm a diagnosis or evaluate specific biomarkers.
Other bodily fluids. Genetic testing is often possible by using a cheek swab, while measuring certain hormones may require blood, urine, or saliva samples. A more invasive option is a cerebrospinal fluid (CSF) analysis, which is obtained using a lumbar puncture and can provide data on neurological biomarkers.
Wearable tech and home devices. Plenty of options are available to help people take an active approach to monitoring digital biomarkers. Smartwatches, for instance, can track your heart rate, sleep patterns, and heart rhythm. Continuous glucose monitors (CGMs) provide real-time blood sugar readings.
The frequency of biomarker monitoring depends on the specific metric in question and its purpose. For instance, a diagnostic biomarker is probably a one-time test, whereas a monitoring biomarker would be repeated regularly.
Your healthcare provider can determine what this looks like in your specific context, which includes factors like:
What’s “normal” for you or your baseline
Symptoms you report and the provider’s clinical observations
Medications or supplements you take
Lifestyle factors, such as diet, exercise, stress, and even recent sleep patterns
Genetic predispositions
The timing of the test and whether you were fasting
Your disease stage and progression
In other words, monitoring is essential, but it’s about more than just collecting one data point in time.
Biomarkers are the language your body uses to communicate what’s happening inside, including early warning signs and treatment progress. Understanding and tracking biomarkers can provide a clearer picture of your health. It can also help you and your provider make smarter, data-driven decisions for prevention, help guide treatment, and optimize your long-term wellness.
A biomarker is the measurable biological substance or change itself — such as blood glucose or a genetic mutation — while a lab test is the tool used to detect or measure that biomarker.
No. While many biomarkers are measured through blood tests, others are detected in urine, saliva, cerebrospinal fluid, tissue samples, or imaging scans. The monitoring method depends on the condition being studied.
Monitoring frequency depends on the biomarker’s purpose and your health context. Some are checked once for diagnosis, while others (like blood pressure or HbA1c) require regular monitoring to manage chronic conditions.
Absolutely. Diet, exercise, sleep, and stress management can positively influence biomarkers like cholesterol, inflammation markers, and blood glucose levels — often improving long-term health outcomes.
Monitoring biomarkers allows healthcare providers to tailor treatments based on how your body, specifically, behaves. This helps to ensure therapies are more effective and minimizes the risk of side effects or ineffective treatment.
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