Bleeding time (BT) is a classic and simple diagnostic test that allows you to assess the functioning of the coagulation system in terms of the ability of capillaries and platelets to form the so-called. primary spigot. How is this examination done? What is too long or too short a bleeding time?

Bleeding time(BT for short) is the time between the wound and the bleeding stopping.

Injury on the surface of our body, which causes damage to the endothelium of blood vessels, activates processes aimed at preventing blood extravasation.

In the first place, due to substances released by the endothelium, local vasoconstriction occurs, followed by activation, adhesion and aggregation of thrombocytes, i.e. platelets, which form a primary plug that obstructs the outflow of blood.

How is bleeding time tested?

In short, bleeding time determination is done by making one or more superficial incisions in your forearm with a lancet.

Then, after the time has started, strips of filter paper are applied to the wounded area at 30-second intervals.

A white strip that has not absorbed blood indicates that the bleeding has stopped and the timing stops. As a rule, the standard is in the range of 4-8 minutes.

The test should be performed on an empty stomach, and taking medications in the period preceding the test should be previously agreed with the physician who orders them.

When will the bleeding time be wrong?

Too long bleeding is a sign of blood clotting disorders at the level of blood vessels and platelets. It can therefore occur in hemorrhagic vascular and platelet defects such as:

  • Thrombocytopenia
  • von Willebrand disease
  • Glanzman's Trombastenia
  • Bernard-Soulier syndrome
  • Afibrinogenemia

Drugs that impair platelet function also have a significant effect on the extension of bleeding time, e.g.

  • Non-steroidal anti-inflammatory drugs (NSAIDs) including acetylsalicylic acid (aspirin)
  • ADP-induced platelet aggregation inhibitors - clopidogrel, ticlopidine

Reducing the bleeding time does not matter

Worth knowing

The advantage of bleeding time testing is that it is easy to perform and the result is quick.

Please note, however, that BT is not very precise and has poor repeatability.

This is due to the fact that its result is influenced by many different factors, including ambient temperature or hematocrit value.

For this reason, BT is currently a very rare test in the diagnosis of bleeding disorders.

Category:

Research