Thrombocytopenia is an atypically low platelet count. Acquired thrombocytopenia is caused by conditions that develop throughout your life instead of genes inherited from birth.

Acquired thrombocytopenia can develop for many different reasons, such as:

  • pregnancy
  • autoimmune disease
  • cancer
  • thrombotic thrombocytopenic purpura, which is a medical emergency that can lead to serious internal bleeding

People with acquired thrombocytopenia may experience easy and severe bleeding and bruising due to a low platelet count. Symptoms often aren’t noticeable if your platelet count is only slightly low.

Read on to learn more about this condition, including causes, symptoms, and treatment options.

A healthy platelet count in adults is between 150,000 and 450,000 platelets per microliter of blood. Thrombocytopenia is characterized by a platelet count below 150,000 platelets per microliter. People with acquired thrombocytopenia develop a low platelet count throughout their lives, as opposed to those with inherited thrombocytopenia caused by genes they receive from their parents.

Your platelet count can drop for several reasons, including:

  • your bone marrow does not produce enough platelets
  • too many platelets are destroyed
  • your spleen holds too many platelets

Acquired thrombocytopenia can be immune or non-immune in origin depending on the underlying cause. Immune causes develop when your immune system attacks and destroys healthy platelets.

Potential immune causes include:

Heparin-induced thrombocytopenia usually occurs between 5 and 10 days after heparin exposure.

Other causes of acquired thrombocytopenia include:

Pregnancy and platelet count

Platelet counts often drop during pregnancy due to increased fluid in your blood and platelet activation. Platelet counts usually drop by about 10% in the third trimester.

Symptoms of acquired thrombocytopenia can include:

If your platelet count drops dangerously low, it can increase your risk of internal bleeding or bleeding in your brain. Bleeding in your brain is called a hemorrhagic stroke. These complications typically only develop when your platelet count drops extremely low.

If acquired thrombocytopenia is caused by thrombotic thrombocytopenic purpura (TTP), there is a risk of developing blood clots in small blood vessels throughout your body that can prevent blood flow to your organs.

TTP generally onsets suddenly and lasts for days to weeks.

It’s essential to see a doctor if you develop signs of thrombocytopenia. They can run tests to check your blood count levels and may be able to prescribe medications to prevent the breakdown of platelets.

Medical emergency

It’s essential to get immediate medical attention if you develop symptoms of cytopenia or symptoms of TTP. Go to the nearest emergency room if you experience:

To diagnose acquired thrombocytopenia, a doctor will:

  • consider your symptoms
  • review your personal and family medical history
  • perform a physical exam

They will also likely order blood tests, such as:

  • a complete blood count to measure your platelet and other blood cell levels
  • a blood smear to look at whether your platelets are damaged
  • a platelet antibody test to measure antibodies produced as a side effect of some drugs like heparin

Treatment for acquired thrombocytopenia depends on the underlying cause. Mild cases may not require treatment.

If your symptoms are caused by a medication, you may need to stop taking that medication. If you have heparin-induced thrombocytopenia, usually you’ll also need to take another medication to stop blood clotting.

Steroids are typically the first-line treatment for immune causes of thrombocytopenia. The most common regimens are 2 to 4 weeks of prednisone or 4 days of dexamethasone (DexPak, Decadron).

Additionally, medications like eltrombopag (Promacta) or romiplostim (Nplate) can help your body make more platelets.

If medications alone are not effective, you may need blood or platelet transfusions, or spleen removal.

TTP requires immediate treatment to avoid life threatening complications. It should ideally be treated with a plasma exchange within 4 to 8 hours. Plasma exchange involves removing the liquid part of your blood to retrieve antibodies or other harmful substances before returning it to your blood.

Most people with immune thrombocytopenia either do not have symptoms or have minor symptoms like frequent nosebleeds or bleeding gums.

Severe bleeding is rare until your platelet count drops below 30,000 platelets per microliter of blood.

In children, thrombocytopenia triggered by viral illness resolves itself in about two-thirds of cases.

Thrombotic thrombocytopenic purpura is a medical emergency that has a mortality rate of over 90% without treatment. Early-on plasma exchange drops the mortality rate to between 10% and 20%.

Thrombocytopenia may not always be preventable.

You can prevent infections that may trigger it by taking steps such as:

  • washing your hands regularly
  • avoiding close contact with people who are sick
  • wearing a facial covering when in close quarters with others, such as on public transport
  • avoiding eating foods past their expiration date

Here are some frequently asked questions people have about acquired thrombocytopenia.

What is the most common cause of acquired thrombocytopenia?

Infections are one of the most common causes of acquired thrombocytopenia. Many viruses can trigger thrombocytopenia, including herpes viruses and the varicella-zoster virus that causes chickenpox.

Can stress cause low platelets?

Mental or physical stress may activate platelets in your blood. This activation can lower the number of platelets circulating through your blood.

How can you increase your platelet count?

Eating an overall health-promoting diet can help support your body’s production of platelets. Some nutrients required for blood cell health include:

Acquired thrombocytopenia is a low platelet count that develops throughout your life. It can be temporary or permanent, depending on the cause.

Many people with thrombocytopenia never develop symptoms, but some people develop life threatening complications like internal bleeding. It’s important to get medical attention if you notice you’re bruising or bleeding easier than usual.