Partial Thromboplastin Time (PTT)
A screening measure of how fast blood clots through the intrinsic pathway, central to investigating unexplained bleeding or clotting.
Consider this test if:
- Easy bruising, frequent nosebleeds, or bleeding that lasts longer than expected
- A previous coagulation test came back with a prolonged PTT that needs explaining
- Recurrent blood clots, unexplained miscarriage, or a question of lupus anticoagulant
- Assessing bleeding risk before a planned surgery or procedure
- On heparin or another anticoagulant and tracking its effect on clotting
- HSA/FSA eligible
- Typical results in about 7 days · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
No fasting required. Tell the ordering clinician about any anticoagulants (heparin, Factor Xa inhibitors, direct thrombin inhibitors) or recent blood thinners, since these prolong the result and affect interpretation. The sample is citrated plasma that must be processed and frozen promptly, so collection happens at a lab equipped to centrifuge and freeze it.
Video consult with your Care Team
A 1:1 call to discuss your health.
What members say on Trustpilot
What this test is for
The activated partial thromboplastin time (aPTT) measures how long plasma takes to clot through the intrinsic and common coagulation pathways. A prolonged result points to a clotting factor deficiency, a clotting factor inhibitor, an anticoagulant such as heparin, or a lupus anticoagulant, while a shortened result is rarely clinically meaningful. This particular workup goes beyond the screening time: it reflexes into the studies that explain an abnormal PTT, including Factor VIII, IX, and XI activity, mixing studies, and lupus anticoagulant testing (DRVVT and hexagonal phase). It is commonly run to evaluate easy bruising, heavy or prolonged bleeding, recurrent clots, or pregnancy loss, and to assess bleeding risk before surgery.
The related PT/INR plus PTT panel pairs this same aPTT with prothrombin time, which screens the extrinsic pathway and monitors warfarin; this item is the deeper PTT-focused coagulation evaluation rather than a routine two-test screen.
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Typical results in about 7 days
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
Everything your health needs,
in one membership
-
Every test at our cost
Members pay our cost on every test, with lab fees passed straight through. The full receipt is itemized, never padded.
-
Continuous tracking, all in one place
Upload past labs and watch your trends over time. Every marker and visit lives in one longitudinal record, so all your care stays together.
-
Year-round clinician support
Text anytime and get clinician-reviewed answers. When you want to go deeper, 1:1 consultations are available at affordable rates.
All for $9/month
Order any test or consult without joining. For $9/month, members unlock member prices, trend tracking, and year-round clinician guidance.
Mito Membership
$9 /mo
cancel anytime
Without membership
$0
pay as you go
At-cost pricing on labs, scans, and more
Priority turnaround on your results
On-demand clinician consults when you need guidance
Personalized action plans across supplements, exercise, nutrition, and sleep
AI health coaching to help you act on your results
Year-round medical support, with in-chat clinician escalation
All your health records in one personal vault, with trends and biological age tracking
Early access to new diagnostics and product releases
More tests to consider
Loading essentials…
Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
Recently viewed
Loading essentials…