How do platelets work

In severe cases, the patient might have to undergo a procedure called a platelet pheresis. This lowers the platelet count by removing the blood, separating out the platelets, and returning the red blood cells back to the body. With secondary thrombocytosis, the symptoms are usually related to the associated condition. For example, if you have an infection or anemia, you treat those conditions and the platelet count comes down.

Symptoms include easy bruising, and frequent bleeding from the gums, nose, or GI tract. Your platelet count drops when something is preventing your body from producing platelets. There are a wide range of causes, including:. If you have too many platelets, it can increase your risk for clotting. But often your cardiovascular risk has more to do with platelet function than platelet number.

Too many platelets, too few platelets, abnormally functioning platelets, and related conditions such as blood clots, strokes, and heart attacks can be inherited.

Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. Platelets, also known as thrombocytes, are blood cells responsible for blood clotting.

If a blood vessel wall becomes damaged, platelets will rush to the site of injury and form a plug or clot to stop the bleeding. If platelet count is low a condition called thrombocytopenia , the risk of uncontrolled or prolonged bleeding increases. When there are too many platelets in the blood a condition called thrombocytosis , it may lead to abnormal blood clot formation, which can be serious and life-threatening.

Your healthcare provider can help you assess your platelet count by looking at a complete blood count CBC test. The root thrombo in thrombocyte means clot. You'll see it used with diseases and conditions that affect platelets and blood clotting. Platelets are one of three types of blood cells in addition to red blood cells and white blood cells that originate in the bone marrow from cells known as megakaryocytes.

The process by which platelets form a clot is called adhesion. In order to stop the bleeding, platelets within that broken vessel adhere to the site of injury and send out chemical signals for more help. Once a plug or clot is formed in the blood vessel wall, the clotting coagulation cascade is activated, which then adds fibrin a structural protein to the clot to knit it together. Fibrin is responsible for the scab you may see at a cut site.

Aspirin and some non-steroidal anti-inflammatory drugs inhibit normal platelet function, which is why you may be asked to stop using them for a period of time before a surgery or procedure.

An overview of the numbers, size, and health of platelets is included in a complete blood count CBC test, a standard lab panel of bloodwork that analyzes the makeup and chemistry of blood. The specific lab markers that refer to platelets are as follows:. Just as it sounds, this is the actual number of platelets you have per microliter of blood.

If your platelet count falls below 50,, you may experience prolonged bleeding times. Platelet count is an important number for your healthcare provider to know before and after surgery to predict any potential bleeding and clotting problems. It is also an important marker during chemotherapy and radiation therapy, as these treatments may inhibit the production of platelets in the bone marrow.

The mean platelet volume MPV is the average size of the platelets. Younger platelets are larger than older ones, so an elevated number means you are producing and releasing them rapidly, while a low number means altered production in the bone marrow.

Platelets are live in the bloodstream for about eight to 10 days. PDW is the variation in the size of the platelets, which can indicate conditions that affect the platelets.

Platelet function tests may also be performed if there are symptoms of or potential for excessive bleeding, and to also monitor anti-platelet medications. If the body doesn't have enough platelets in circulation, you may develop a condition called thrombocytopenia. Other examples of conditions that may cause thrombocytopenia include having a mechanical heart valve, heparin antibodies, chronic alcohol abuse, liver disease, severe sepsis, and toxic exposures.

The causes have remained elusive probably because in most cases, thrombocytopenia is considered a sufficient explanation of the bleeding diathesis and further studies are not performed.

Goerge et al now provide experimental evidence that inflammation is a potent trigger of hemorrhage in thrombocytopenia. This finding confirms that there is no clear correlation between bleeding time and bleeding risk. In vivo fluorescence microscopy revealed the onset of bleeding in the cutaneous Arthus reaction as soon as 20 minutes after the inflammatory challenge. Similar effects were also observed in models of endotoxin-induced lung inflammation and, notably, a model of ischemic brain infarction.

This intriguing observation directly demonstrates for the first time that platelets are required for the maintenance of vascular integrity in inflammation, and also shows that thrombocytopenia alone is not sufficient to cause spontaneous hemorrhage. Thus, maintenance of vascular integrity in inflammation and platelet plug formation appear to be mechanistically distinct processes. Based on this hypothesis, one might speculate that inhibitors of firm platelet adhesion and aggregation could efficiently prevent occlusive thrombus formation without increasing the risk of spontaneous bleeding.

This sounds like wishful thinking, but indeed, recent studies have shown that inhibition of GPIb or GPVI profoundly protects mice from ischemic stroke without increasing the risk of intracranial hemorrhage.

The study does not clarify how platelets contribute to the maintenance of vascular integrity, but the authors propose an involvement of locally delivered vasoactive mediators released from storage granules during transient interaction with the inflamed vessel wall.

It can be anticipated that the current work will stimulate intense research to test this hypothesis. Sign In or Create an Account.

Sign In. Skip Nav Destination Content Menu. Article Navigation. How do platelets prevent bleeding?