Coagulation

The results of the CBC can alert your doctor if you have anemia or a low platelet count, which can interfere with your ability to clot.

Fibrinogen is a protein made by your liver. This test measures how much fibrinogen is in your blood. Abnormal results may be a sign of excessive bleeding or hemorrhage. Other names for this test include factor I and hypofibrinogenemia test.

Prothrombin is another protein your liver produces. The prothrombin time (PT) test measures how well and how long it takes your blood to clot. It normally takes about 25 to 30 seconds. It may take longer if you take blood thinners. Other reasons for abnormal results include hemophilia, liver disease, and malabsorption. It’s also useful in monitoring those who take medications that affect clotting, such as warfarin (Coumadin).Results are given in the number of seconds it takes the blood to clot.

Sometimes the PT test uses a calculation called the international normalized ratio (INR) to compare results of different laboratories. Your doctor will usually order the PT test along with another clotting test called an activated partial thromboplastin time (aPTT)

This test analyzes how quickly small blood vessels in your skin close up and stop bleeding. It’s performed differently than the other blood tests.
A blood pressure cuff will be placed on your upper arm and inflated. Your healthcare provider will make a couple of tiny cuts on your lower arm. The cuts won’t be deep and will generally feel like scratches.

Your healthcare provider will remove the cuff when it’s deflated and briefly place blotting paper on the cuts every 30 seconds until bleeding stops.
Bleeding usually lasts between one to nine minutes. The test is considered safe and carries few side effects or risks

Thrombin time measures how well fibrinogen is working. Abnormal results may be due to inherited fibrinogen disorders, liver disease, some cancers, and medications that affect clotting