Prothrombin Time (PT) with INR & PTT
Prothrombin Time (PT) with INR & PTT is a laboratory test you can order directly. The prothrombin time (PT) with INR and partial thromboplastin time (PTT) is a group of blood clotting tests. It is ordered to check how well your blood clots and to monitor conditions or medicines that affect clotting.
- Sample type
- blood
- Category
- Coagulation
- Turnaround
- 1-3 business days
- Price
- $49
- Referral
- Not required
The prothrombin time (PT) with INR and partial thromboplastin time (PTT) is a group of blood clotting tests. It is ordered to check how well your blood clots and to monitor conditions or medicines that affect clotting.
What it measures
- Prothrombin Time (PT) — Time in seconds for blood to clot via the extrinsic pathway.
- INR — Standardized ratio of PT to normal, used to monitor warfarin and liver function.
- Partial Thromboplastin Time (PTT) — Time in seconds for clotting via the intrinsic pathway.
- Fibrinogen — Sometimes measured; a protein essential for clot formation.
Who it is for
A doctor may order this test if you have unexplained bleeding or bruising, a known clotting disorder, or are taking blood-thinning medicine like warfarin or heparin.
Preparation
No fasting is needed. Tell your doctor about all medicines, especially blood thinners, and follow any specific instructions about timing.
Results and what they mean
Results are reported as seconds for PT and PTT, and as a number for INR. Your clinician interprets these values based on your health and medicines. This is general information, not medical advice.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the prothrombin time (pt) with inr & ptt is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
What does a high INR mean?
A high INR means your blood clots more slowly than normal, which can increase bleeding risk. Your doctor will determine the cause and next steps.
Do I need to stop my blood thinner before the test?
No, unless your doctor tells you to. The test is often used to check if your dose is right.
How long does it take to get results?
Typically 1 to 3 business days, but it may be faster in urgent situations.
Can I eat or drink before the test?
Yes, no fasting is required. You can eat and drink normally.