Why is D-dimer high? Causes, symptoms, and what to do

D-dimer is a protein fragment that is produced when a blood clot dissolves in the body. It is often measured to help diagnose conditions related to abnormal clotting. High levels of D-dimer can indicate various health issues, so understanding what causes an increase and what steps to take is important.

What is D-dimer?

D-dimer is a protein fragment that results from the breakdown of a blood clot. When the body forms a clot, it eventually needs to dissolve it, and D-dimer is one of the byproducts of this process. It is measured in nanograms per milliliter of fibrinogen equivalent units (ng/mL FEU). While a small amount of D-dimer can be normal, especially as you age, elevated levels can signal a problem.

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Causes of High D-dimer Levels

Several factors can cause elevated D-dimer levels:

• Blood Clots: Conditions like deep vein thrombosis (DVT) or pulmonary embolism (PE) often result in high D-dimer.
• Surgery or Trauma: Recent surgery or injury can temporarily raise D-dimer levels.
• Pregnancy: During pregnancy, D-dimer levels naturally increase.
• Infections or Inflammation: Acute infections or inflammatory conditions can elevate D-dimer.
• Liver Disease: The liver plays a role in clot breakdown, and liver dysfunction can affect D-dimer levels.

Understanding D-dimer Test Results

D-dimer levels are typically considered normal if they are less than 500 ng/mL FEU. However, as you age, the threshold for what is considered high may increase. For individuals over 50 years old, a common calculation is age multiplied by 10 to determine the upper limit of normal.

Symptoms Associated with High D-dimer

High D-dimer itself does not cause symptoms, but it can be associated with conditions that do. Symptoms to watch for include:

• Swelling or pain in the legs: This may indicate DVT.
• Shortness of breath or chest pain: These could be signs of a PE.
• Persistent cough or coughing up blood: Also associated with PE. If you experience any of these symptoms, it is important to seek medical advice.

Frequently asked questions

What does a D-dimer test measure? The D-dimer test measures the amount of D-dimer in the blood, which helps indicate if there is an abnormal level of clotting activity in the body.

Can D-dimer levels be high for reasons other than blood clots? Yes, factors like recent surgery, pregnancy, infections, and liver disease can also elevate D-dimer levels.

Is a high D-dimer level always a cause for concern? Not necessarily. While it can indicate serious conditions, other non-threatening factors can also raise levels. It is important to discuss results with a healthcare professional.

When to see a doctor

If you have a high D-dimer result, especially if accompanied by symptoms like leg swelling, chest pain, or difficulty breathing, it is important to consult a healthcare provider. They can assess whether further testing or treatment is needed based on your overall health and risk factors.

Decisions regarding health conditions and test results should always be made in consultation with a healthcare provider.