What is the Bicarbonate Test?

The Bicarbonate test measures the concentration of bicarbonate (HCO₃⁻) in the blood, a key buffer that helps maintain the body’s acid–base balance. Bicarbonate works with the lungs and kidneys to keep blood pH within a narrow, healthy range.

Bicarbonate levels are closely linked to kidney function, lung function and overall metabolic status. Abnormal levels can indicate disorders affecting acid production, acid elimination or bicarbonate regulation.

This test is commonly included as part of electrolyte panels and metabolic profiles.

Why do I need a test for Bicarbonate?

You may need this test if there is concern about acid–base imbalance, kidney disease or respiratory conditions. It is frequently used to investigate unexplained fatigue, breathing difficulties or electrolyte abnormalities.

Bicarbonate testing helps identify metabolic acidosis or alkalosis and supports diagnosis and monitoring of kidney, lung and systemic conditions.

Symptoms and scenarios where testing is recommended:

• Chronic kidney disease
• Shortness of breath or respiratory disorders
• Persistent fatigue or weakness
• Vomiting or diarrhoea
• Electrolyte imbalance
• Suspected metabolic acidosis or alkalosis
• Monitoring intensive or chronic illness
• Use of certain medications affecting acid balance

Benefits of the Bicarbonate Test

• Assesses acid–base balance
  Key marker of metabolic pH regulation.
• Supports kidney function evaluation
  Kidneys play a major role in bicarbonate control.
• Aids diagnosis of metabolic disorders
  Identifies acidosis or alkalosis.
• Useful in respiratory disease assessment
  Reflects compensation for lung-related pH changes.
• Monitors chronic disease progression
  Important in kidney and lung disease management.
• Guides treatment decisions
  Helps adjust fluids, medications or ventilation.
• Simple and widely used blood test
  Part of routine metabolic panels.
• Supports electrolyte interpretation
  Complements sodium, potassium and chloride results.

Step-by-Step: How Testing Works

Choose your preferred testing method

You can attend one of our UK partner clinics or arrange a home or hotel visit with a mobile phlebotomist.

Option 1 – In-Clinic Blood Draw

1. Select your nearest UK clinic and book an appointment.
2. A clinician or phlebotomist collects a venous blood sample.
3. The sample is analysed for bicarbonate concentration.
4. Results are delivered securely online.

Option 2 – Home or Hotel Phlebotomy (+£60)

1. Book a UK-wide home or hotel visit at a convenient time.
2. A trained phlebotomist collects your blood sample on-site.
3. The sample is transported to the laboratory.
4. Results are uploaded digitally without the need to travel.

Your Results Explained

Low Levels

Low bicarbonate levels suggest metabolic acidosis or reduced acid buffering.
This may be seen in kidney disease, uncontrolled diabetes or severe diarrhoea.
Typical UK reference range: ~22–29 mmol/L.

Normal Levels

Normal bicarbonate levels indicate balanced acid–base regulation.
This suggests normal kidney and respiratory compensation.

High Levels

High bicarbonate levels suggest metabolic alkalosis or compensation for chronic respiratory disease.
Causes may include prolonged vomiting, diuretic use or chronic lung conditions.