Dalteparin Anticoagulation Monitoring (Anti-Xa Activity)
This test measures how well your blood is prevented from clotting after receiving a medication called dalteparin, which is often used to prevent blood clots in certain medical situations.
["Helps ensure your medication is working safely to prevent clots without excessive bleeding risk."]
Key facts at a glance
- LOINC
- 12475-0
- Short code
- D-ALA Ur-mRate
- Synonyms
- D-ALA Ur-mRate
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your healthcare provider may order this test if you’ve been prescribed dalteparin—a type of low-molecular-weight heparin—to prevent blood clots, such as deep vein thrombosis (DVT) or pulmonary embolism. It helps adjust your dose to balance clot prevention and bleeding risks, especially in patients with kidney issues or those on other medications.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or vein to draw blood. The process takes a few minutes, and you may feel slight discomfort. If you’re on dalteparin, your provider will coordinate timing with your medication schedule to avoid interference.
What the Results Mean
Results show the activity level of your dalteparin in your blood, measured in anti-Xa units. Lower-than-expected levels may indicate insufficient clot prevention, while dangerously high levels could increase bleeding risk. Your provider will interpret results in the context of your medical history and treatment plan.
Common Reasons for Testing Variations
If your dalteparin dose is too low, you might experience symptoms like swelling, pain, or new blood clots. If it’s too high, you could have excessive bleeding, bruising, or unusual nosebleeds. Your provider will adjust your medication based on these results and your overall health.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Regular monitoring of dalteparin activity is critical for patients at high risk of clots (e.g., post-surgery, with heart disease, or after trauma). It ensures the medication’s effectiveness without causing dangerous bleeding. Misaligned levels can lead to life-threatening complications, so consistent testing is vital for personalized care.
Short name
Anti-Xa Factor Level
Frequently asked questions
When might I need this test retested?
How soon will I get my results?
Can I stop dalteparin if my test results look normal?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy