Activated Partial Thromboplastin Time (aPTT)
Activated Partial Thromboplastin Time (aPTT) explained
aPTT evaluates the intrinsic coagulation pathway and is used to assess bleeding disorders and monitor heparin therapy.
Varies by laboratory (LDT/CLIA; not FDA‑approved as a drug)Activated Partial Thromboplastin Time (aPTT) helps treat
• Bleeding/clotting disorder evaluation
• Heparin monitoring
• Pre‑operative screening
additional medications
• Related clinical evaluation and history
• Repeat testing to confirm abnormal results
• Additional targeted labs as recommended
medication risks
• False positives/negatives leading to unnecessary anxiety or missed diagnoses
• Privacy and insurance implications depending on results
• Pre‑analytical variables (fasting, meds) can affect accuracy
side effects
• Bruising or soreness at draw site
• Lightheadedness or fainting (rare)
• Infection at puncture site (very rare)
FAQs
Q: Fasting?A: Not required.
Q: Sample handling?
A: Proper collection and processing are critical.
Q: Medications?
A: Heparin and others prolong aPTT.
Q: Mixing studies?
A: May be done for unexplained prolongation.
Q: Insurance?
A: Covered when indicated.
