Definition

A platelet test is a procedure conducted to measure the number of platelets (blood platelets) in the blood. Platelets are smaller than both red and white blood cells but play a crucial role in blood clotting or coagulation. Coagulation is a process that helps to stop ongoing bleeding after a wound occurs by forming a clot. Platelets work together with clotting factors (proteins in the blood) to form a type of "glue" that seals the wound and prevents further bleeding.

Low platelet levels, which fall below the normal range, are referred to as thrombocytopenia. This condition can cause continuous or excessive bleeding after an injury. On the other hand, high platelet levels above the normal range are known as thrombocytosis. This condition can lead to excessive clotting, which may result in blood clots that could block blood flow in the body’s blood vessels, leading to potentially dangerous complications.

A platelet test is usually ordered by a doctor if there are symptoms suggestive of thrombocytopenia or thrombocytosis. Symptoms of thrombocytopenia include prolonged or excessive bleeding after injury, frequent nosebleeds, bleeding gums, red spots on the skin, and unusually long or heavy menstrual periods. Symptoms of thrombocytosis may include tingling in the hands and feet, headaches, dizziness, and weakness in certain body parts.

Platelet test is commonly done to monitor or diagnose conditions that cause excessive bleeding. It is also requested if you are scheduled to undergo a complex surgery or if you are taking medications that affect blood clotting. The platelet test is often performed along with a complete peripheral blood test or a complete blood count (CBC), which may include tests for leukocytes, hematocrit, or hemoglobin.

Indication

This test is typically performed under the following conditions:

• To help diagnose platelet-related diseases when symptoms or clinical signs suggest their presence.

• To monitor platelet levels in patients undergoing treatment for specific conditions.

• As part of routine screenings during medical check-ups.

Contraindication

There are no specific contraindications or conditions that would prevent someone from undergoing the platelet test.

Preparation Before the Test

No special preparation is required for the platelet test, and it can be performed without fasting. However, it is advised to consult with a healthcare provider before the test, as certain conditions might interfere with the test results and lead to inaccurate readings.

Test Procedure

For the platelet test, a blood serum sample of 0.25 to 0.5 milliliters is typically required. The blood is drawn from a vein and collected into a designated tube. Laboratory personnel will wear gloves and appropriate personal protective equipment (PPE) when collecting the sample.

Before taking the blood sample, the technician will apply an elastic band around the upper arm and clean the area where the needle will be inserted with antiseptic. Blood is commonly drawn from the crease of the elbow. Once the blood has been collected and placed in the tube, the elastic band will be removed, and the puncture site will be pressed and cleaned with antiseptic gauze. The entire process usually takes only a few minutes. The collected blood sample is then analyzed using specialized equipment in the laboratory, and the results are typically available within a few hours.

Normal and Abnormal Values

The normal range for platelet values varies by age and gender.

Adult Male

Adult Female

Children

Infants or Neonates

However, each laboratory may have slightly different reference ranges, depending on the equipment or techniques used.

Results and Recommendations (Follow-up Tests)

Low Platelet Levels

If your platelet test results show low values, it is important to consult a doctor. Low platelet levels, or thrombocytopenia, indicate an insufficient number of platelets needed for proper blood clotting. Low platelet counts may be linked to infections, cancer, or other underlying health problems.

Medical conditions that may cause low platelet levels include viral infections such as measles or hepatitis, vitamin B12 deficiency, bone marrow infections, blood cancers like leukemia, liver disease, or autoimmune disorders.

Although low platelet counts may suggest certain health conditions, it is crucial not to self-diagnose. You should seek medical advice and undergo a physical examination if you experience any symptoms or signs that are concerning.

Normal Platelet Levels

If your platelet test results fall within the normal range, it suggests that you likely do not have any hematological issues and that you are maintaining a healthy lifestyle. Continue with your current habits to preserve your health and prevent any conditions that could lead to abnormal hematocrit levels.

High Platelet Levels

If your platelet test results show elevated values, it is essential to consult with a doctor. Your healthcare provider may recommend adjustments to your diet and lifestyle to improve your health, or even suggest medications to help lower your hematocrit levels.

High platelet levels are also known as thrombocytosis, a condition where there is an excessive number of platelets in your body. High platelet levels can be a risk factor for stroke.

Medical conditions that can cause thrombocytosis are anemia, inflammatory bowel disease, arthritis caused by autoimmune factors (rheumatoid arthritis), viral or bacterial infections, certain types of cancer such as lung cancer or breast cancer.

Even though a high platelet value may suggest certain conditions, self-diagnosis is not recommended. It is important to consult with a healthcare provider for proper evaluation and treatment if you experience any concerning symptoms.

Consult the Right Doctor

Adults with abnormal platelet test results can consult with a general practitioner, who can conduct further testing or begin appropriate therapy based on the diagnosis. If necessary, you may also seek advice from an internist or hematology-oncology specialist for a more thorough discussion regarding your platelet levels. In pediatric cases, any abnormal test results should be reviewed with a pediatrician.

Looking for more information about laboratory, radiology, and other examination results? Click here!