The platelet count test, also known as the PLT (platelet) blood test, is a diagnostic test that measures the number of platelets present in a blood sample. Platelets are tiny, round cell fragments that play an essential role in blood clotting. Abnormal platelet levels, either too high or too low, as indicated by the results of the platelet count test, can suggest an underlying health condition that affects blood clotting. This, in turn, can indirectly impact other bodily functions and organs. Appropriate treatment may be necessary to manage the platelet count.

What is a PLT blood test? 

A platelet count test involves evaluating a blood sample in a laboratory to assess the number of platelets present. This information allows doctors to interpret the actual platelet count in the body. Platelets also referred to as thrombocytes, are responsible for promoting blood clotting and stopping bleeding in response to cuts, bruises, or internal injuries. 

A low platelet count indicates insufficient platelets in the body, making it challenging for the body to control excessive bleeding. Conversely, a high platelet count detected through a blood test may lead to the formation of blood clots within blood vessels. These clots can dislodge and travel to various locations such as the lungs, intestines, brain, or heart, potentially causing severe medical conditions.

Types of Platelet Tests

Platelet tests are laboratory assessments that help evaluate the number and function of platelets in the blood. Common platelet tests include:

• Platelet Count: This test measures the number of platelets in a given volume of blood. It is a crucial component of the complete blood count (CBC) and helps assess the risk of bleeding or clotting disorders.
• Mean Platelet Volume (MPV): MPV measures the average size of platelets. Changes in MPV can indicate various conditions, such as platelet production disorders or increased platelet destruction.
• Platelet Distribution Width (PDW): PDW measures the range of platelet sizes in a blood sample. It provides additional information about platelet size variation, which may be associated with certain medical conditions.
• Platelet Aggregation Test: This functional test evaluates how well platelets stick together to form a blood clot. It helps assess platelet function and is often used in investigating bleeding disorders or monitoring antiplatelet therapies.
• Bleeding Time Test: While less commonly used today, this test measures how long it takes for bleeding to stop after a small incision is made. It provides information about platelet function and can help diagnose certain bleeding disorders.
• Platelet Function Assay: Various assays exist to assess specific aspects of platelet function, including aggregometry, flow cytometry, and PFA-100 (Platelet Function Analyzer-100). These tests help evaluate platelet adhesion, activation, and aggregation.
• Platelet Antibody Tests: These tests detect antibodies against platelets and are useful in diagnosing immune-mediated disorders affecting platelets, such as idiopathic thrombocytopenic purpura (ITP).

Purpose of the PLT blood test

The primary purpose of a PLT blood test is to assess the blood's clotting ability using a blood sample. Typically, the platelet count test is conducted as part of comprehensive test panels like the complete blood count (CBC) test. Nevertheless, the PLT means in blood tests can also be performed independently as a routine check-up procedure. A doctor might recommend a platelet count test for the following reasons:

• Diagnosing blood clot disorders
• Evaluating blood clotting functionality before a surgical procedure
• Monitoring individuals undergoing specific medical treatments, such as blood thinners or chemotherapy

How is a Platelet Count Test Done?

A phlebotomist collects the blood sample from the patient. The obtained blood sample is then placed in a vial and subjected to laboratory testing using a machine. Within a matter of minutes, the machine can furnish the platelet count and quantities of other blood cells.

Uses of the PLT Test

The PLT test, which stands for Platelet Count, is a component of the complete blood count (CBC) and is used for various diagnostic purposes. The PLT test measures the number of platelets in a given volume of blood. Platelets are small cell fragments that play a crucial role in blood clotting. Here are the primary uses of the PLT test:

• Assessment of Overall Health: The PLT test is a routine part of the CBC, which provides an overview of a person's overall health. It helps healthcare providers identify potential issues such as infections, anemia, and various blood disorders.
• Evaluation of Bleeding or Clotting Disorders: Abnormal platelet counts can indicate potential bleeding or clotting disorders. Low platelet counts (thrombocytopenia) may lead to increased bleeding tendencies, while high platelet counts (thrombocytosis) can contribute to excessive clotting.
• Monitoring Medical Treatments: Individuals undergoing certain medical treatments, such as chemotherapy or radiation therapy, may experience changes in their platelet counts. The PLT test helps monitor these changes and guides treatment adjustments if necessary.
• Diagnosis of Platelet Disorders: The PLT test is essential in diagnosing conditions that specifically affect platelets, such as immune thrombocytopenia (ITP) or thrombotic thrombocytopenic purpura (TTP). These conditions can result in abnormal platelet counts.
• Preoperative Assessment: Before surgeries or medical procedures, healthcare providers may order a CBC with PLT to assess a person's overall health and ability to form blood clots.
• Monitoring Medications: Certain medications, such as those used to treat blood disorders or to prevent clotting, may impact platelet counts. Regular PLT tests help healthcare providers adjust medication dosages as needed.
• Screening for Diseases: Changes in platelet counts can be indicative of underlying diseases or conditions. The PLT test is valuable for screening and identifying potential health issues, allowing for early intervention and management.

What do High Platelet Count Levels mean?

High platelet count can be due to infections, immune system issues, genetic conditions influencing platelet production, and potentially certain cancers. 

When does the doctor recommend a Platelet Count Test?

A doctor might recommend a platelet count blood test during a routine physical examination or if they suspect that a patient is suffering from thrombocytopenia (low platelet count) or thrombocytosis (high platelet count).

What are the symptoms of Low & High Platelet Count Levels?

Symptoms of high and low platelet counts differ in terms of the blood's clotting ability. Essentially, a low platelet count in a blood test is associated with an inability to clot effectively, potentially leading to symptoms such as:

• Bleeding from the nose or mouth
• Abnormally prolonged bleeding after an injury
• Appearance of small red or purple dots on the skin
• Heavy bleeding, especially during menstruation
• Passing blood along with urine or stool

Having a high platelet count in a blood test is related to a condition of excessive blood clotting, which may cause symptoms such as:

• Weakness
• Dizziness
• Chest pain
• Unexplained headache
• Tingling sensation in the hands and feet
• Swelling, pain, tenderness, and a warm feeling in the extremities
• Shortness of breath
• Confusion and memory changes
• Fever

Platelet Count Test Results

The platelet count obtained from a PLT blood test is best interpreted by a doctor, utilising the reference range provided for the specific platelet test. Platelet counts can vary among different populations; for instance, females may exhibit different platelet counts than males, and similarly, younger individuals may display different platelet counts than older ones. Having more than the normal range of platelets in a platelet count test is known as thrombocytosis, while having less than the normal range of platelets is called thrombocytopenia.

What is the Normal Range for Platelet Count Levels?

The standard range for the quantity of platelets in the blood falls between 1,50,000 and 4,00,000 platelets per microliter. Counts exceeding these upper and lower limits can be categorised as PLT blood test high or low platelet counts in the blood.

What can cause Low & High Platelet Count Levels?

Having higher or lower than normal levels of platelets can result from various factors. Some of the risk factors associated with a low platelet count include:

• Certain medications
• Specific genetic conditions
• Pregnancy
• Viral or bacterial infections
• Aplastic anaemia
• Certain cancers like lymphoma and leukaemia
• Enlarged spleen
• Heavy alcohol consumption

An increase in platelet count might be attributed to factors including:

• Iron deficiency or hemolytic anaemia
• Certain inflammatory diseases
• Specific cancers
• Rare genetic conditions
• Severe blood loss
• Bone marrow disorders
• Adverse reactions to medications
• Physical activity

What do I do if I have Low & High Platelet Count Levels?

A high platelet count in the blood might not always require treatment, as the levels generally return to normal once the underlying condition is resolved. If any symptoms are present, doctors can manage them as they treat the root cause. In certain cases, doctors might suggest specific medications to reduce platelet levels, especially if symptoms are linked to essential thrombocythemia. If the platelet levels in the blood become dangerously high, a procedure called plateletpheresis could be performed to remove platelets.

For individuals with PLT blood test low levels, treatment might not be necessary if symptoms are either absent or not severe. However, when severe symptoms are present, doctors might recommend treatment using certain medications to address the underlying cause. Additional treatments for a low platelet count could include:

• Plasma exchange
• Blood or platelet transfusion
• Surgical removal of the spleen (splenectomy)

Conclusion

Platelets are crucial for blood clotting, and imbalances—either too high or too low—can lead to various complications. Treating doctors may recommend appropriate interventions to address the underlying causes and ultimately resolve high or low platelet count conditions in the blood.

FAQs

1. What is the platelet count test cost?

Ans. The cost of a platelet count test may vary depending upon the lab and the city where the test is done but may range anywhere between Rs. 50 and Rs. 200.

2. What level of platelets is considered dangerous?

Ans. Having a very low platelet count, less than 20,000, can be dangerous as it can cause internal bleeding.

Reference:
https://www.testing.com/tests/platelet-count/
https://my.clevelandclinic.org/health/diagnostics/21782-platelet-count#:~:text=A%20 platelet%20account%20is%20a,for%20blood%20 clots%20 or%20 stroke.