No, there is currently no blood test or other diagnostic tool that can provide a conclusive diagnosis of Parkinson’s disease.

But over the past few years, different groups of researchers have been investigating whether changes in blood proteins or chemicals could be linked to Parkinson’s disease.

Several studies have identified changes in certain proteins and cells that are directly associated with Parkinson’s disease.

In a 2024 study in 207 participants, researchers used a mass spectrometry assay to analyze blood samples and examine eight different proteins associated with Parkinson’s disease severity. These include:

  • granulin precursor
  • mannan-binding-lectin-serine-peptidase-2
  • endoplasmic-reticulum-chaperone-BiP
  • prostaglandin-H2-D-isomerase
  • intercellular-adhesion-molecule-1
  • complement C3
  • dickkopf-WNT-signalling pathway-inhibitor-3
  • plasma-protease-C1-inhibitor

The study included three groups of participants:

  1. They had a Parkinson’s disease diagnosis.
  2. They had REM sleep disorder, which often precedes Parkinson’s disease.
  3. They had no Parkinson’s disease or any signs of the disease.

The pattern of blood test results helped researchers cluster participants within each of the three groups, suggesting there may be changes among people who have Parkinson’s disease or who will later develop the disease that can be detected with blood tests.

In a 2025 study, the researchers found that elevated blood levels of RGTTCRA-tRFs and lower levels of reduced mitochondrial-originated tRFs were a sign of early Parkinson’s disease.

A high ratio of these specific transfer RNA fragments (tRFs) may impact dopamine production and weaken mitochondrial protection, two key aspects in preventing Parkinson’s disease.

The researchers suggested that this blood test may be a safe, effective, and affordable diagnostic tool for catching Parkinson’s disease early.

Despite these positive findings, it’s important to note that the results are inconsistent and not reliable enough to be used as diagnostic tools for Parkinson’s disease.

With more research, the significance and reliability of testing might improve enough to be used for Parkinson’s disease, but we don’t have enough evidence at this time.

There’s no definitive diagnostic tool for Parkinson’s disease.

A doctor will perform several physical examinations to check for changes in motor skills and involuntary movements. They’ll also check your medical history to see if you’re taking any medications that may be causing symptoms.

In some cases, a doctor may order imaging tests like an MRI, X-ray, or ultrasound to help rule out other conditions.

Experts are continuing to explore possible ways in which blood testing could be used to detect Parkinson’s disease earlier. This, along with physical examinations, may help identify the disease sooner and can even help develop treatments.