The Plasma Viscosity Blood Test measures the thickness (viscosity) of blood plasma and is used to detect systemic inflammation, infection, and immune-related conditions. It is an alternative inflammatory marker to ESR and CRP and is performed in a UKAS-accredited laboratory, with an optional GP consultation.

What is a Plasma Viscosity Test?

Plasma viscosity reflects how thick the liquid portion of blood is. It is influenced by levels of plasma proteins such as fibrinogen and immunoglobulins, which increase during inflammation, infection, or autoimmune disease.

Unlike ESR, plasma viscosity:

• Is not affected by age or red blood cell size

• Is more stable over time

• Can be used reliably to monitor chronic inflammatory conditions

This test is commonly used in the investigation and monitoring of:

• Autoimmune diseases

• Chronic infections

• Inflammatory disorders

• Paraproteinaemias (e.g. multiple myeloma)

At London Blood Tests, plasma viscosity is measured using validated viscometric techniques in line with UK haematology standards.

Benefits of the Plasma Viscosity Test

1. Reliable Marker of Inflammation
   Detects systemic inflammatory activity.

2. Alternative to ESR
   Less affected by age, anaemia, or pregnancy.

3. Useful in Autoimmune Disease Monitoring
   Helps track disease activity over time.

4. Supports Infection Investigation
   Elevated levels may indicate acute or chronic infection.

5. Stable & Reproducible Results
   Ideal for long-term monitoring.

6. Non-Invasive Blood Test
   Requires only a simple blood draw.

7. Optional GP Consultation for Interpretation
   Results reviewed with a GP if required.

Why Do I Need a Plasma Viscosity Test?

You may benefit from this test if you have:

• Persistent fatigue

• Unexplained fever or weight loss

• Joint pain or stiffness

• Suspected autoimmune disease

• Chronic inflammatory conditions

• Abnormal ESR or CRP results

Conditions where plasma viscosity is useful include:

• Rheumatoid arthritis

• Polymyalgia rheumatica

• Lupus

• Vasculitis

• Chronic infection

Because inflammatory diseases can be subtle or fluctuating, plasma viscosity provides a consistent marker of inflammatory burden.

How the Test Works

In-Clinic Testing at London Blood Tests

1. Book Your Appointment

   • Online or phone booking

   • No fasting required

2. Pre-Test Review

   • Inform the clinician of current symptoms or diagnoses.

3. Sample Collection

   • Venous blood sample collected by a trained phlebotomist

   • Takes 5–10 minutes

4. Laboratory Analysis

   • Sample analysed in a UKAS-accredited laboratory

5. Quality Control

   • Results validated before release

6. Results Delivery

   • Results typically available within 1–2 business days

7. Optional GP Consultation

   • Discuss results and further investigation if needed

At-Home Blood Draw (Home or Hotel Phlebotomy – UK-Wide)

1. Book a Phlebotomist Visit

   • Convenient home or hotel appointment

2. Professional Collection

   • Sample collected safely and discreetly

3. Secure Transport

   • Sample couriered same day

4. Laboratory Testing

   • Same analysis as clinic testing

5. Results & Follow-Up

   • Results delivered online, GP review optional

Your Plasma Viscosity Results – Explained

Plasma viscosity is reported in mPa·s (millipascal seconds).

Typical UK reference range:

• 1.50 – 1.72 mPa·s

Interpretation:

• High plasma viscosity: inflammation, infection, autoimmune disease, paraproteinaemia

• Normal plasma viscosity: no significant systemic inflammation

• Low plasma viscosity: uncommon and usually not clinically significant

Results are often interpreted alongside CRP, ESR, full blood count, and immunoglobulins.