Alzheimer’s disease is a neurodegenerative condition that can cause difficulties with thinking and memory and physical decline. Biomarkers can help experts monitor its development, progression, and treatment response.

Alzheimer’s disease (“Alzheimer’s” for short) is a neurodegenerative condition that primarily affects your brain.

Neurodegeneration — the progressive deterioration of nerve cells — happens in Alzheimer’s when abnormal protein deposits called beta-amyloid plaques and tau tangles form in your brain.

Alzheimer’s is the most common cause of dementia, which is a significant decline in thinking ability that affects daily functioning. But because Alzheimer’s typically emerges late in life, people often mistake its early symptoms for natural age-related physical and mental changes.

For this reason, biomarkers are becoming increasingly important in the treatment of Alzheimer’s. These measurable indicators can help you get a diagnosis as early as possible and can allow doctors to personalize your Alzheimer’s management plan through careful monitoring.

Biological markers, or biomarkers, are measurable indicators of your body’s function. Biomarkers include a variety of biological factors, from the level of a specific molecule to visible changes in the structure of organs and tissues.

In disease management, biomarkers are “red flags” that a disease process, such as Alzheimer’s, is happening, progressing, or responding to treatment.

Healthcare professionals can monitor Alzheimer’s through several biomarkers, including the following:


Amyloid-beta is a protein byproduct produced during natural cellular metabolism. Elevated levels of this protein in your body are considered a precursor to and an indication of Alzheimer’s disease processes.

Amyloid-beta protein plaques in your brain that are visible on diagnostic imaging are a diagnostic feature of Alzheimer’s.

Tau protein

Tau protein’s role in your body is to help stabilize the structure of neurons. In Alzheimer’s, tau protein dysfunction can create abnormal structural “tangles” inside neurons, promoting cell death.

Elevated tau protein levels or visible deposits of this protein can provide insight into the development and progression of Alzheimer’s.

Neurofilament light (NFL)

NFL is another type of structural protein found in neurons. When neurons are damaged or die, this protein is released into your cerebrospinal fluid (CSF), the colorless liquid that surrounds your brain and spinal cord.

The presence of NFL in a CSF sample can indicate that neurodegenerative processes such as Alzheimer’s are occurring.

Inflammatory markers

Your body’s inflammatory response involves multiple measurable substances, such as cytokines, proteins, and chemokines.

Some of these pro-inflammatory substances, including interleukin-6, tumor necrosis factor-alpha, and C-reactive protein, have been linked to Alzheimer’s development, progression, and therapeutic response.

Most biomarkers for Alzheimer’s are detected through CSF analysis or diagnostic imaging techniques, but blood biomarkers are an area of ongoing research.

According to a 2023 research review, phosphorylated tau (p-tau) in blood plasma may be one blood biomarker that accurately distinguishes Alzheimer’s from other neurodegenerative conditions.

P-tau is a tau protein that has undergone phosphorylation, a process in your body that combines phosphates with amino acids for use in cellular regulatory functions.

While no blood biomarkers are currently being used routinely in clinical practice, many are being investigated. Other blood biomarkers being evaluated include those that screen for specific beta-amyloid and inflammatory indicators.

Biomarkers can be important diagnostic tools in a comprehensive Alzheimer’s disease assessment.

Biomarkers can indicate disease-related changes in your body before physical symptoms become noticeable or structural changes in your brain become visible on other tests. They also convey very precise, specific information that can be relevant in distinguishing one disease from another.

For example, the presence of amyloid-beta plaques can indicate Alzheimer’s rather than another type of dementia, such as frontotemporal dementia.

These features make biomarkers invaluable in the early detection of Alzheimer’s disease and in differentiating early stages of Alzheimer’s from other forms of dementia that may have similar onset features.

The following biomarker tests are currently available for Alzheimer’s disease:

CSF testing

CSF testing involves using a sample of your CSF to measure levels of amyloid-beta and tau protein.


Diagnostic imaging tools look for visible changes in your brain, such as the buildup of amyloid-beta plaques or the presence of tau tangles. These tests can also show overall changes in your brain related to disease processes, such as brain atrophy or a decrease in tissue size and integrity.

Common neuroimaging tests include:

  • MRI scans
  • CT scans
  • positron emission tomography (PET) scans
  • fluorodeoxyglucose (FDG)-PET scans

Genetic risk profiling

Several genes may be involved in the pathology of Alzheimer’s, including APOE-e4, a gene that is associated with the strongest risk in certain groups of people.

Genetic profiling can help doctors find out whether you have genetic variations associated with Alzheimer’s.

Biomarkers for Alzheimer’s are an area of ongoing research. While blood biomarkers continue to be a priority because of their accessibility and affordability compared with current methods, new diagnostic imaging strategies, genetic screenings, and novel detection techniques are also being explored.

Some experts believe that artificial intelligence and machine learning will one day also be part of biomarker screening and prediction of Alzheimer’s.

Biomarkers in Alzheimer’s disease are measurable factors in your body that indicate disease development, progression, and therapeutic response.

Protein levels, genetics, inflammatory markers, and structural changes in your brain are all examples of Alzheimer’s biomarkers.

While current Alzheimer’s biomarkers are assessed using CSF analysis, genetic testing, or neuroimaging, research into blood biomarkers and innovative screening methods is underway.