Fibrinogen Test

A fibrinogen test measures how much fibrinogen is present in the blood. It is also called fibrinogen test, plasma fibrinogen test, factor I test, and hypofibrinogenemia test.

Fibrinogen is produced by the liver and helps with blood clotting. Abnormal levels of fibrinogen are seen in conditions such as afibrinogenemia (no fibrinogen), hypofibrinogenemia (low fibrinogen), dysfibrinogenemia (fibrinogen that does not work properly), and hypodysfibrinogenemia (low levels of fibrinogen that do not work properly). Doctors use this test to identify these fibrinogen disorders and start the right treatment.

You may be advised to get the fibrinogen test if you are experiencing the following symptoms of a bleeding disorder:

• Heavy bleeding after a medical procedure
• Frequent nosebleeds
• Blood in the urine or stool
• Frequent and large bruises on the skin
• Heavy menstrual periods

You may also be advised to get the fibrinogen test if you are experiencing the following symptoms of excessive blood clotting:

• Swelling, redness, pain, and warmth in your arms and legs
• Nausea
• Trouble breathing

The following categories of people are also highly advised to get the test:

• Individuals with liver disease – Liver disease is one of the common causes of dysfibrinogenemia (fibrinogen is dysfunctional).
• Pregnant women – Fibrinogen normally increases during pregnancy. A markedly low fibrinogen level in suspected placental abruption (placenta separates from the uterine wall) or obstetric haemorrhage (excessive bleeding) can be clinically important and may help assess the severity of the condition. It is not generally a routine screening test for all pregnant women.

The fibrinogen test can be used to help detect a few medical conditions, such as:

• Afibrinogenemia – This is a condition in which there is no fibrinogen circulating in the body.
• Hypofibrinogenemia – This is a condition where the levels of circulating fibrinogen are lower than normal.
• Dysfibrinogenemia – In this condition, the fibrinogen does not work properly in the body.
• Hypodysfibrinogenemia – In this condition, there is less fibrinogen than normal, and it does not function properly.

What to Expect Before the Fibrinogen Test

No fasting is required for a standalone fibrinogen test. You can eat and drink normally. However, if it is part of a broader package that includes fasting tests, your doctor may advise fasting for 8-12 hours. Avoid strenuous exercise for 24 hours before the test, as intense physical activity can temporarily raise fibrinogen levels and affect interpretation. Always inform your doctor about any ongoing medications.

What to Expect During the Blood Collection

A phlebotomist cleans the skin with an antiseptic, then places an elastic band around your upper arm to make the veins easier to access. A small needle is inserted into the vein; you may feel a brief pinch. Blood is collected into a labelled tube in under a minute.

What to Expect After the Fibrinogen Test

A small cotton swab and bandage are placed over the site to stop any minor bleeding. You can return to normal activities immediately. Minor bruising is normal and disappears quickly. If dizzy, sit and rest for a few minutes.

In the fibrinogen test, the primary parameter being measured is:

• The level of fibrinogen in the blood.

The fibrinogen test normal range is indicated in the table below.

Note: Normal values may differ slightly between laboratories. A doctor should always interpret the results.

The fibrinogen test is a simple blood test. However, it has some risks and limitations that should be known:

Risks:

Although it is a simple blood test, it has some minor risks, as with any other blood test. The blood collection process can cause bleeding, bruising, or minor sores as side effects. However, most of these go away quickly.

Limitations:

• The results may be altered in older individuals, females, pregnant women, and post-menopausal women.
• The results may be affected by some drugs and other factors before testing.

Depending on your medical condition and symptoms, you may be advised to get additional medical tests such as:

• Factor VIII activity
• Coagulation factor tests
• D-dimer test
• MPV blood test
• Platelet count
• Prothrombin time test
• X-ray of the veins
• CT scan