Quick answer
The Activated Partial Thromboplastin Time (APTT) Test costs ₹670 at Live Line Health Care. Times how long your plasma takes to clot through the intrinsic pathway, used to monitor heparin and look into bleeding disorders such as haemophilia. No fasting is needed. It uses a blood sample and the report is usually ready the same day.
Also known as: Activated Partial Thromboplastin Time, Partial Thromboplastin Time, PTT, PTTK, Kaolin Cephalin Clotting Time
What is the APTT Test?
The Activated Partial Thromboplastin Time (APTT) test measures how many seconds your plasma takes to form a clot after the lab adds chemicals that start the process. It checks the intrinsic and common pathways of clotting, which rely on factors VIII, IX, XI and XII along with factors II, V and X and fibrinogen. A result longer than expected means one or more of these proteins is low, is not working well, or is being blocked by a medicine or antibody.
Doctors rely on APTT in three main situations. In hospital, it guides the dose of unfractionated heparin, a fast-acting blood thinner given through a drip or injection. For a child or adult with unusual bleeding, it is a first step in looking for haemophilia or von Willebrand disease. For women with repeated miscarriages or anyone with unexplained clots, a long APTT can raise suspicion of lupus anticoagulant, an antibody that, confusingly, prolongs the test yet makes clots more likely. It does not track warfarin well, which is the job of PT/INR, and the newer blood thinners usually need no routine APTT monitoring.
What it measures: The time your plasma takes to clot through the intrinsic and common clotting pathways, in seconds, compared with a control.
Parameters included (2)
- APTT (seconds)
- Control Time
Why is this test done?
- Adjusting the dose of unfractionated heparin
- Looking for haemophilia A or B, or von Willebrand disease
- Investigating unexplained bleeding, along with PT/INR and a platelet count
- Checking clotting before surgery when a doctor asks for it
- Looking for lupus anticoagulant after repeated miscarriages or unexplained clots
When should you get tested?
- Bleeding into joints or muscles, especially in boys and young men
- Long bleeding after circumcision, tooth removal or injury
- Very heavy periods from the first period onward
- Repeated miscarriages or a blood clot at a young age
- A family history of haemophilia or another bleeding disorder
How to prepare for the APTT Test
- 1Food does not change this result, so eat as normal.
- 2Tell staff the name of any blood thinner and the time of your last dose, especially heparin or tablets such as dabigatran, rivaroxaban or apixaban. Do not stop one before the test unless your doctor advises it.
- 3Mention any family history of bleeding and any heavy bleeding in the past, which helps your doctor read the result.
APTT Test normal range
| Parameter | Typical reference range |
|---|---|
| APTT | 25–35 secondsdepends on the reagent; compare with the control on your report |
| Target on unfractionated heparin | About 1.5–2.5 times the controlyour hospital team sets the target |
APTT varies more between laboratories than INR does, and it has no standard ratio like the INR, so the range on your own report matters most. Ranges are typical adult values and vary between labs, age and sex. Always use the range printed on your report and discuss results with your doctor.
Understanding your results
- A prolonged APTT with a normal PT suggests a problem in the intrinsic pathway, such as low factor VIII, IX or XI, heparin, or lupus anticoagulant.
- When both APTT and PT are prolonged, doctors consider the common pathway, severe liver disease, vitamin K deficiency, DIC or a high level of a blood thinner.
- A mixing study may follow. If adding normal plasma corrects the result, a factor shortage is likely. If it does not, an inhibitor such as lupus anticoagulant is more likely.
- A short APTT is usually not significant and can reflect high factor VIII during acute illness or pregnancy. Your doctor will decide whether it needs follow-up.
- A normal APTT does not fully rule out mild haemophilia or von Willebrand disease, so specific factor tests may still be advised if your history is suggestive.
Health packages that include this test
The APTT Test is included in these full body checkups:
APTT Test – FAQs
What is the price of the APTT Test?
The Activated Partial Thromboplastin Time (APTT) Test costs ₹670 at Live Line Health Care, at all 45 centres and for home sample collection.
Are APTT and PTT the same test?
In everyday use, yes. PTT was the older form, and APTT adds an activator to the tube, which makes the result faster and more consistent. Prescriptions may also say PTTK. If your doctor writes any of these, this is usually the test they mean. Confirm with them if you are unsure.
Why is APTT long but PT normal?
That pattern points to proteins used only by the intrinsic pathway, including factors VIII, IX and XI. Common causes are heparin, haemophilia, von Willebrand disease and lupus anticoagulant. Some people have a harmless low factor XII. Your doctor will usually repeat the test and may add a mixing study or factor assays.
Can lupus anticoagulant cause a high APTT without bleeding?
Yes. It is an antibody that interferes with the lab reagent, so the clotting time looks long even though the real risk in the body is clots rather than bleeding. It is worth discussing after repeated miscarriages or unexplained clots. Separate tests are needed to confirm it.
Is APTT used for warfarin?
Not routinely. Warfarin and acenocoumarol are monitored with PT/INR, which responds to them more reliably. APTT is mainly used for unfractionated heparin in hospital, and low molecular weight heparin usually does not need it. If you are unsure which test your blood thinner needs, ask the doctor who prescribed it.
Can a child have this test for suspected haemophilia?
Yes. A doctor may suggest it if a child has large bruises, long bleeding after circumcision or swollen, painful joints. A long APTT does not confirm haemophilia by itself, as factor VIII and IX tests are needed. A paediatrician or haematologist should review the result with the family history.
What should I do if my APTT is high?
Share the result with your doctor, along with a list of your medicines. A mildly high value may simply be repeated first, as a difficult sample or a blood thinner can cause it. Go to emergency care if you have heavy bleeding, black stools or a severe headache.
Where can I get the APTT Test done?
At any of our 45 Live Line Health Care centres in 40 cities across Andhra Pradesh and Telangana, including Hyderabad, Visakhapatnam, Warangal, Kakinada and Nellore, or book home sample collection.
Medical disclaimer: This information is for general awareness only and is not a substitute for professional medical advice. Please consult a qualified doctor to interpret your results and before starting or changing any treatment.