Also called: PTT, aPTT, Blood coagulation test
Report
{context.blood_test.parameters} Parameters
What it checks
Report delivery
Test for
Age group
Commonly advised for
The Activated Partial Thromboplastin Time (APTT) test measures the time taken for blood to clot through the intrinsic and common coagulation pathways. It evaluates the function of several clotting factors produced mainly by the liver and is an essential test for assessing bleeding or clotting disorders.
APTT is also widely used to monitor patients receiving heparin therapy and to investigate unexplained bleeding tendencies or recurrent miscarriages.
Why Is This Test Recommended?
A healthcare provider may order an APTT test for several vital clinical reasons:
Monitoring Heparin Therapy: This is the most common use. Patients on "unfractionated heparin" (a blood thinner) require regular APTT checks to ensure their dosage is high enough to prevent clots but low enough to avoid dangerous bleeding.
Pre-Surgical Screening: To ensure a patient can safely undergo surgery without the risk of excessive intra-operative bleeding.
Investigating Unexplained Bleeding: Identifying the cause of frequent nosebleeds, heavy menstrual cycles, or bleeding gums.
Evaluating Easy Bruising: Determining if "black and blue" marks are appearing due to a lack of clotting proteins.
Screening for Genetic Disorders: Detecting deficiencies in factors VIII, IX, and XI, which are associated with conditions like Hemophilia A and B.
Checking for Inhibitors: Identifying the presence of "Lupus Anticoagulant" or other antibodies that interfere with the body's natural clotting process.
Symptoms or Conditions That May Require an APTT Test
You may be advised to undergo this test if you experience symptoms related to abnormal hemostasis:
Prolonged Bleeding from Minor Cuts: A simple scratch or shaving nick that oozes for an unusually long time.
Recurrent Nosebleeds (Epistaxis): Spontaneous nosebleeds that are difficult to stop with standard pressure.
Heavy or Prolonged Menstrual Bleeding: Periods lasting more than a week or involving very large clots.
Easy Bruising: Developing large bruises from very minor bumps or even without known injury.
Swollen, Painful Joints: This can be a sign of internal bleeding into the joint spaces (hemarthrosis), common in undiagnosed clotting factor deficiencies.
Blood in Urine or Stool: Unexplained internal bleeding that appears in bodily waste.
How Is the Test Performed and Prepared For?
A venous blood sample is collected. No fasting is required. Patients should inform the doctor about blood-thinning medications.
What Does the APTT Test Measure?
The test specifically monitors the performance of the following clotting factors:
Factor XII (Hageman factor)
Factor XI
Factor IX (Christmas factor)
Factor VIII
Common Pathway Factors: Factors X, V, II (Prothrombin), and I (Fibrinogen).
By observing how long it takes for these factors to produce a fibrin web, the lab determines your "clotting speed."
What Do the Results Mean?
Results are reported in seconds. While ranges depend on the specific chemical reagents used by a laboratory, general benchmarks are:
Normal Range: Typically between 25 to 35 seconds. This suggests that the intrinsic and common pathways are functioning correctly.
Prolonged APTT (High): This means the blood is taking longer than normal to clot. This could be due to:
Heparin use.
Clotting factor deficiencies (like Hemophilia).
Liver disease (the liver makes most clotting factors).
Presence of "Lupus Anticoagulant" antibodies.
Vitamin K deficiency (though this usually affects the PT test more).
Shortened APTT (Low): This is less common but may occur during an acute inflammatory response or immediately after an injury when the body is in a "hyper-clotting" state.
Consistent Vitamin K Intake: If you are on certain blood thinners, keep your intake of green leafy vegetables (spinach, kale) consistent. Drastic changes can flip your clotting times.
Stay Active: Regular movement prevents blood from pooling in the legs, which reduces the risk of clots that might require blood-thinning medication.
Alcohol in Moderation: Excessive alcohol can damage the liver, which is the "factory" for your clotting proteins.
Dental Safety: If you have a known prolonged APTT, use a soft toothbrush and inform your dentist before any procedure to prevent excessive gum bleeding.
Home Safety: Reduce tripping hazards in your home to prevent falls that could lead to internal bruising or joint bleeds.
Frequently Asked Questions (FAQs)
Is APTT used for clotting or bleeding?
Both; APTT assesses clotting function to identify bleeding disorders and also helps evaluate thrombotic risk in certain conditions.
Does it monitor heparin therapy?
Yes, APTT is the standard test for monitoring unfractionated heparin therapy, ensuring the dosage is therapeutic and safe.
Can pregnancy affect results?
Mildly; pregnancy can cause slight changes in coagulation factors, though significant abnormalities still require investigation.
Is fasting needed?
No, fasting is not required for APTT testing as it measures clotting function, not metabolic parameters.
Is repeat testing common?
Yes, repeat testing is common for monitoring anticoagulant therapy, tracking treatment response, or confirming initial abnormal results.
The aPTT test checks how long your blood takes to clot. It is advised if:
Tapadia Diagnostic Centre in Visakhapatnam offers NABL-accredited Activated Partial Thromboplastin Time test from a Blood (plasma) sample(s). PTT, aPTT, Blood coagulation test is also prescribed for Easy bruising, bleeding, blood in waste. Established in 1989, this doctor-led diagnostic centre ensures high accuracy. Home sample collection and walk-in facility available at our Visakhapatnam center. Pay at the centre with no advance payment. Book online or visit us.
Activated Partial Thromboplastin Time in Visakhapatnam
Rated 4.6 on Google
From 6,477 patient reviews across our Hyderabad centres.
Every report, kept for you
Past reports stay in your account and can be downloaded again.
NABL accredited
Every result reviewed by a qualified pathologist before it reaches you.
Four decades of practice
A family-run diagnostic centre, trusted by doctors and households since 1989


Activated Partial Thromboplastin Time in Vijayawada
Activated Partial Thromboplastin Time in Visakhapatnam
Activated Partial Thromboplastin Time in Ahmedabad
Activated Partial Thromboplastin Time in Bengaluru
Activated Partial Thromboplastin Time in Mumbai
Activated Partial Thromboplastin Time in Secunderabad
Activated Partial Thromboplastin Time in Karimnagar
Activated Partial Thromboplastin Time in Hyderabad
Activated Partial Thromboplastin Time in Warangal
Activated Partial Thromboplastin Time in Aurangabad
HIV 1 & 2 Antibodies, Serum-Elisa Method in Visakhapatnam
Dengue IgG, IgM Antibodies + NS1 Antigen-Rapid, Serum in Visakhapatnam
Lipoprotein A (Lp A), Serum in Visakhapatnam
Erythrocyte Sedimentation Rate (ESR) in Visakhapatnam
Thyroxine Total (T4), Serum in Visakhapatnam
Triiodothyronine Total (T3), Serum in Visakhapatnam
CA 19.9 (Pancreatic Cancer Marker), Serum in Visakhapatnam
NIPT with Microdeletions in Visakhapatnam
NIPT Basic in Visakhapatnam
Complete Blood Picture (CBP) in Visakhapatnam
Serum Phosphorus Test in Visakhapatnam
TIBC in Visakhapatnam
Urology Profile in Visakhapatnam
Beta HCG Free, Serum (Pregnancy Test) in Visakhapatnam
Viral Screening in Visakhapatnam
AFP Test in Visakhapatnam
Microalbuminuria test in Visakhapatnam
Diabetes Testing (FBS + PLBS) in Visakhapatnam
Antithrombin III in Visakhapatnam
D-dimer test in Visakhapatnam
Creatine Kinase (CK) Test in Visakhapatnam
AST Test in Visakhapatnam
Cardiac Markers in Visakhapatnam
Pap Smear - LBC in Visakhapatnam
DVT Profile in Visakhapatnam
Bleeding Time and Clotting Time (BT & CT) in Visakhapatnam
Estradiol Test in Visakhapatnam
hs-CRP Test in Visakhapatnam
Alkaline Phosphatase (ALP) Test in Visakhapatnam
Fertility Profile in Visakhapatnam
Albumin blood test in Visakhapatnam
Troponin T in Visakhapatnam
Infertility Profile Extended in Visakhapatnam
Electrolyte Panel in Visakhapatnam
Anticardiolipin Antibodies (IgG) in Visakhapatnam
PSA Test in Visakhapatnam
FSH Test in Visakhapatnam
STD Panel in Visakhapatnam
PCOS Profile in Visakhapatnam
Serum Iron Test in Visakhapatnam
Cardiac Profile-III in Visakhapatnam
Plasma Fibrinogen Test in Visakhapatnam
HBsAg Test in Visakhapatnam
Cardiac Biomarker Test in Visakhapatnam
Herpes Simplex Virus (HSV) Types 1 and 2 Antibody Test in Visakhapatnam
Antenatal Profile in Visakhapatnam
Activated Partial Thromboplastin Time in Visakhapatnam
Lipid Panel in Visakhapatnam
Fine Needle Aspiration Cytology in Visakhapatnam
CRP test in Visakhapatnam
Joint Pain / SLE / Collagen Profile-I in Visakhapatnam
PAPP-A Test in Visakhapatnam
Insulin Test in Visakhapatnam
Triple Screen Test in Visakhapatnam
Anti-HCV Test in Visakhapatnam
Basic Metabolic Panel (BMP) in Visakhapatnam
Very low-density lipoprotein (VLDL) test in Visakhapatnam
Free Testosterone in Visakhapatnam
Triglycerides Test in Visakhapatnam
Quad Screen in Visakhapatnam
Folic Acid in Visakhapatnam
Urinalysis in Visakhapatnam
CEA Test in Visakhapatnam
Ferritin Test in Visakhapatnam
Transferrin Saturation% in Visakhapatnam
Protein C Antigen in Visakhapatnam
Alpha Feto Protein (AFP) - Fluid in Visakhapatnam
CPK (MB) Test in Visakhapatnam
Lupus Anticoagulant Testing in Visakhapatnam
Reticulocyte Count in Visakhapatnam
Infertility Profile-Basic in Visakhapatnam
Beta hCG Test in Visakhapatnam
DIABETIC PROFILE in Visakhapatnam
LH Test in Visakhapatnam
Anti-Müllerian Hormone (AMH) Test in Visakhapatnam
Bile Salts and Bile Pigments, Urine in Visakhapatnam
HbA1c in Visakhapatnam
Vitamin D (1,25-Dihydroxyvitamin D) in Visakhapatnam
Liver Function Test (LFT) in Visakhapatnam
Anemia Profile Basic in Visakhapatnam
Rheumatoid Factor in Visakhapatnam
Widal Test in Visakhapatnam
Bilirubin blood test in Visakhapatnam
Inhibin A, Tumor Marker, Serum in Visakhapatnam
Thyroid Function Tests in Visakhapatnam
eGFR in Visakhapatnam
Menopause Profile in Visakhapatnam
EXTENDED DIABETIC PROFILE in Visakhapatnam
LDH Test in Visakhapatnam
Total Cholesterol Test in Visakhapatnam
Random Blood Sugar Test in Visakhapatnam
Total Protein Test in Visakhapatnam
RPR test in Visakhapatnam
Anti-dsDNA Test in Visakhapatnam
HDL Cholesterol in Visakhapatnam
Blood Type Test in Visakhapatnam
ASO Titre in Visakhapatnam
Blood Urea(Serum) Test in Visakhapatnam
Postprandial Blood Sugar Test in Visakhapatnam
Back Pain Profile in Visakhapatnam
ANA test in Visakhapatnam
Serum Creatinine Test in Visakhapatnam
PT/INR Test in Visakhapatnam
Fasting Blood Sugar Test in Visakhapatnam
Extended Anemia Profile III Executive in Visakhapatnam
Kidney Function Test (Renal Profile) in Visakhapatnam
Serum Magnesium Test in Visakhapatnam
Well-woman exam in Visakhapatnam
LDL cholesterol test in Visakhapatnam
Prolactin Test in Visakhapatnam
Malaria Blood Smear in Visakhapatnam
Liver Function Test (+GGT) in Visakhapatnam
TPHA Test in Visakhapatnam
Hepatitis B Surface Antigen (HBsAg) Test in Visakhapatnam
Antenatal Profile 2 in Visakhapatnam
TSH Test in Visakhapatnam
Cardiac Catheterization in Visakhapatnam
Cardiolipin Antibody (IgM) in Visakhapatnam
Master Health Checkup in Visakhapatnam
Calcium Profile in Visakhapatnam
Coagulation Profile in Visakhapatnam
Uric Acid Test in Visakhapatnam
Vitamin D (25 - Hydroxy Vitamin D, Serum) in Visakhapatnam
Globulin Test in Visakhapatnam
Fever Profile Test in Visakhapatnam
Connective Tissue Disease Profile in Visakhapatnam
Calcium Blood Test in Visakhapatnam
IHC in Visakhapatnam
Estriol Unconjugated (E3) Test in Visakhapatnam
Blood Typing in Visakhapatnam
Vitamin B12 Test in Visakhapatnam
Serum Cortisol in Visakhapatnam
Double Marker Test in Visakhapatnam
Pap Smear, Conventional in Visakhapatnam
Protein S Activity in Visakhapatnam
Non-Invasive Prenatal Testing (NIPT) in Visakhapatnam
whole exome sequencing in Visakhapatnam
Newborn Screening (NBS) in Visakhapatnam
Renal Function Test (RFT) in Visakhapatnam