Low platelet count: what your result means

What platelets do

Platelets are tiny blood cells that stick together to plug a cut and stop bleeding. A complete blood count (CBC) reports how many you have. Indian and Pakistani reports often show the count in lakh/cumm, so 1.5 to 4.5 lakh/cumm matches the usual range of 150 to 450 ×10³/µL. MPV is the average size of your platelets. When the body is using up platelets quickly, it releases younger, larger ones, so MPV can be higher. A low MPV with a low count can point to the bone marrow making fewer platelets, though MPV is only a clue.

Common causes of a low platelet count

The cause is often short-term, such as an infection. Sometimes platelets clump together in the blood tube and the machine counts too few, which is called pseudothrombocytopenia. A repeat sample, sometimes in a different tube, sorts this out. When the count is truly low, your doctor will look for the reason, and a recent fever, new medicines, alcohol use and any history of liver disease are all useful clues.

• Viral infections, especially dengue, and malaria
• Some medicines, including certain antibiotics and heparin
• Liver disease or an enlarged spleen
• Immune thrombocytopenia (ITP), where the immune system destroys platelets
• Pregnancy, low B12 or folate, or heavy alcohol use
• Less often, bone marrow disorders

Dengue and low platelets

In dengue, platelets often fall around days 3 to 7, usually as the fever is settling. This is the time to watch most closely. Warning signs include severe belly pain, vomiting that does not stop, bleeding from the gums or nose, blood in vomit or stool, feeling very tired or restless, fast breathing, and cold or clammy skin. Drink plenty of fluids and follow your doctor's advice on daily blood counts. The WHO advises avoiding aspirin and ibuprofen-type painkillers when dengue is suspected, so ask a doctor which medicine is safe for fever.

What usually happens next

Your doctor will look at how low the count is, whether you have symptoms, and the rest of your blood count. A mild drop with no bleeding often just needs a repeat test. A count between 100 and 150 ×10³/µL rarely causes problems on its own. Signs of bleeding include easy bruising, tiny red or purple dots on the skin (petechiae), nosebleeds, bleeding gums and heavy periods. If the count stays low or keeps falling, your doctor may order tests for the cause. Platelet transfusion is used only in certain situations and is not decided by the number alone.

Questions to ask your doctor

• What do you think is causing my low platelets?
• Should the test be repeated to rule out clumping in the tube?
• How often should my platelets be checked, and what number would worry you?
• Are any of my medicines or painkillers unsafe with a low count?
• Which bleeding signs should make me come back straight away?