There is no single test that can diagnose Alzheimer’s disease. Instead, doctors use a combination of assessments to rule out other potential causes and make a definitive diagnosis.

Diagnosing Alzheimer’s involves a comprehensive assessment to identify cognitive decline and rule out other potential causes of memory impairment. This involves both clinical evaluations and brain imaging scans.

Read on to learn more about the techniques doctors use to diagnose Alzheimer’s.

A nurse watching an older man with dementia use toys at a table in his home.Share on Pinterest
Getty Images

Diagnosing Alzheimer’s disease involves a multi-faceted approach to distinguish cognitive decline from typical age-related memory changes or other cognitive disorders.

The process begins with a thorough medical history assessment, where the doctor collects information about the individual’s symptoms, family history, and overall health.

A detailed discussion with the person and their family members can provide valuable insights into the progression of their cognitive decline.

Next, the doctor conducts a clinical evaluation to assess the person’s cognitive function, memory, language abilities, problem-solving skills, and other mental capacities. Various standardized cognitive tests and assessments can evaluate different aspects of cognitive performance.

Brain imaging techniques, such as MRI and CT scans, allow doctors to visualize the brain’s structure and rule out tumors or strokes.

Sometimes, doctors may perform cerebrospinal fluid (CSF) analysis to detect specific biomarkers relating to Alzheimer’s.

In contrast to some other medical conditions, there is no single, straightforward test that can conclusively diagnose Alzheimer’s disease.

However, there has been intensive research on developing a blood test to diagnose the condition. Scientists have made promising strides toward this, but currently, health organizations do not recognize any blood test as a stand-alone diagnostic tool for Alzheimer’s disease.

Some ongoing studies are exploring blood biomarkers to diagnose the disease, but more research is necessary to prove this is reliable.

An Alzheimer’s diagnosis typically involves the following tests:

  • Clinical evaluation: This initial step allows the doctor to gain insights into the progression of cognitive decline and potential risk factors.
  • Neurological exam: During this exam, physicians closely evaluate the person for conditions that may impair memory or thinking. They test the person’s reflexes, sensation, coordination, muscle tone and strength, eye movement, and speech.
  • Cognitive tests: A series of standardized cognitive tests and neuropsychological assessments can evaluate various aspects of cognitive function, such as memory, language abilities, attention, and problem-solving skills. These tests help identify any cognitive deficits and determine the extent of cognitive impairment.
  • Brain imaging: MRI or CT scans help rule out other conditions, such as brain tumors or strokes, that could contribute to cognitive impairment.
  • PET scans with radiotracers: These scans use radiotracers that bind to plaques in the brain. These protein deposits often characterize Alzheimer’s disease.
  • CSF analysis: In some cases, doctors may perform a lumbar puncture to collect CSF from the lower back. This analysis can reveal specific biomarkers that have links to Alzheimer’s, such as elevated levels of beta-amyloid and tau proteins, providing valuable insights into the underlying changes in the brain.

The diagnostic process for Alzheimer’s can help rule out some other potential explanations for a person’s symptoms at the same time as testing for the disease itself.

For example, brain imaging studies may reveal abnormalities, such as tumors or bleeding, that could mimic Alzheimer’s symptoms.

A doctor may also identify potential signs of drug or alcohol misuse during their assessment. They could also identify medications a person is taking that could impair thinking as a side effect.

However, if other causes exist, doctors may order additional tests. For example, they may order blood tests to check for conditions that can affect cognitive function, such as:

  • vitamin deficiencies
  • thyroid disorders
  • infections
  • diabetes
  • kidney or liver problems

When doctors diagnose Alzheimer’s, they use specific terms to indicate the certainty of the diagnosis and the stage of the disease. These terms help communicate the confidence level in the diagnosis and guide further treatment plans.

The three categories are:

  • Possible Alzheimer’s: This means there is evidence of cognitive impairment, but the doctor cannot confirm the exact cause for sure.
  • Probable Alzheimer’s: This means doctors are fairly confident that Alzheimer’s disease is the most likely cause of a person’s symptoms.
  • Proven Alzheimer’s: Doctors use this term when they can confirm the diagnosis with a high degree of certainty.

Following a diagnosis of Alzheimer’s, doctors will work with the patient and their family to create a personalized care plan. The program considers the stage of the condition, the specific needs of the person, and their current circumstances.

The plan may include:

  • medications to manage symptoms or slow disease progression
  • education about Alzheimer’s and what to expect
  • regular monitoring of the symptoms
  • information about legal and financial planning
  • support to enhance the person’s quality of life

The aim of treatment is to maintain a person’s independence for as long as possible. It will also aim to provide them with compassionate support throughout the individual’s journey with Alzheimer’s disease.

Coming to terms with an Alzheimer’s diagnosis can be difficult for people and their loved ones. Individuals may feel anger, grief, anxiety, or fear.

While adjusting to this new diagnosis, it may help to join a support group or speak with a therapist. Some people find it beneficial to start making a memory book with their loved one.

Learn more about dementia.

There is no simple test that can diagnose Alzheimer’s with certainty. Instead, diagnosing the condition involves multiple assessments and tests. These tests evaluate cognitive function and can help rule out other potential causes of memory impairment.

The diagnosis itself can range from “possible Alzheimer’s” to “proven Alzheimer’s,” depending on how sure doctors are that the condition is the cause of the symptoms.

Following diagnosis, doctors create personalized care plans for the patient, which may include medication, support, and regular monitoring.