Lactate (Lactic Acid) (LAC)

What is Lactate (Lactic Acid)?

Lactate is a byproduct of anaerobic metabolism that occurs when cells don’t receive enough oxygen or during intense exercise. It’s produced when glucose is broken down without sufficient oxygen, serving as an important indicator of tissue oxygenation and metabolic stress. Elevated lactate can signal serious medical conditions requiring immediate attention.

Why is it Tested?

Doctors order lactate to evaluate tissue perfusion, diagnose metabolic disorders, and assess critically ill patients. It’s crucial for detecting lactic acidosis, monitoring sepsis, and evaluating patients with unexplained acidosis. Lactate levels help guide treatment in emergency and intensive care settings.

Normal Ranges

Reference ranges vary by lab and collection method. General guidelines:

Adults: 0.5–2.2 mmol/L

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low Lactate

Low levels are generally not clinically significant but may indicate:

Good tissue oxygenation
Proper cellular metabolism
Effective circulation

High Lactate

Elevated lactate indicates tissue hypoxia or metabolic stress and may point to:

Sepsis or severe infection
Shock (cardiogenic, hypovolemic, or distributive)
Liver disease or failure
Certain medications (metformin, beta-agonists)

How to Track Over Time

Lactate monitoring is crucial in acute care settings where rapid changes can indicate clinical deterioration or improvement. Serial measurements help assess response to treatment, guide fluid resuscitation, and predict outcomes in critically ill patients. Trending lactate levels provides valuable insight into tissue perfusion status.