Low Platelet Count (Thrombocytopenia): Causes, Signs and Testing

What it involves

MedlinePlus explains that thrombocytopenia means there is an abnormally low amount of platelets. Platelets are parts of the blood that help it clot, and the condition is sometimes associated with abnormal bleeding. The encyclopedia divides causes into not enough platelets made in the bone marrow, increased removal in the bloodstream, and increased trapping in the spleen or liver.

Who this is for

• Adults whose complete blood count showed a low platelet number.
• Patients who bruise easily, have frequent nosebleeds or bleeding gums.
• People with liver disease, an enlarged spleen or a vitamin deficiency.
• Anyone starting or stopping medicines and wondering how they affect blood counts.

What to expect

• Questions about bleeding, bruising, recent illness, alcohol, new medicines and family history
• An exam for bruises, small red spots, an enlarged spleen or signs of liver disease
• Repeat blood work, including a complete blood count, which the practice offers
• A referral to a hematologist, or to the ER, when counts are very low or bleeding is serious

Often found on routine blood work

The encyclopedia says you may not have any symptoms, so a low count is often noticed on a complete blood count ordered for another reason. The complete blood count guide explains what the platelet line on that report means, and the annual physical guide explains why routine labs are drawn. A single low number is usually repeated before anyone draws conclusions, because tubes can clump and give a falsely low reading.

What it can feel like

MedlinePlus lists bleeding in the mouth and gums, bruising, nosebleeds and petechiae, a rash of red spots typically on the extremities. Easy bruising is the most common reason people book a visit, and it has its own list of causes in the easy bruising guide. Nosebleeds are covered in the nosebleeds guide. Tiredness can come along with the underlying cause, as the anemia guide explains.

Why platelets run low

The encyclopedia names bone marrow conditions such as aplastic anemia, leukemia and myelodysplastic syndrome, folate and vitamin B12 deficiency, and medicines such as chemotherapy among the reasons the marrow makes too few. Platelets can be used up by serious illness, drug reactions or immune conditions in which the body destroys them. An enlarged spleen can trap them, as in cirrhosis, which the cirrhosis guide describes. The fatty liver guide and the alcohol use screening guide relate to the liver.

How it is worked up

A provider asks about bleeding, medicines and alcohol, examines the skin and belly, and repeats the count. MedlinePlus lists a complete blood count, clotting tests called PTT and PT, and a review of the blood under the microscope, and says bone marrow aspiration or biopsy may help diagnose some causes. The practice offers blood work, and the bone marrow tests, which are done by specialists, are arranged by referral. The liver function tests guide often come along with this work-up.

Treatment depends on the cause

According to MedlinePlus, treatment depends on the cause, and in some cases a transfusion of platelets may be required to stop or prevent bleeding. The outlook also depends on the disorder behind the low count. Until a cause is clear, a provider may advise you to avoid medicines that affect bleeding unless prescribed, such as aspirin and anti-inflammatory pain relievers, and to be careful with activities that risk injury. Never stop a prescribed blood thinner without asking.

When to get urgent help

Severe bleeding is the main complication, according to MedlinePlus, and it may occur in the brain or the gastrointestinal tract. Call 911 or go to the ER for bleeding that will not stop after 10 minutes of pressure, vomiting blood, black or bloody stools, a sudden severe headache, confusion, or a fall with a head injury. Make an appointment for unexplained bruising or bleeding, and see the blood in stool guide for bowel bleeding.

Sources

• MedlinePlus: Thrombocytopenia (encyclopedia)