Lupus may cause you to experience low platelet counts. This could be a direct result of the disease or due to some lupus medications. Severe cases can be life threatening, but most cases are mild and don’t require treatment.

Lupus is an autoimmune disease that causes inflammation and damage in various tissues throughout the body, including your joints, skin, and internal organs.

Lupus can also cause issues with your blood cells, such as:

  • low red blood cell (RBC) counts and anemia
  • low white blood cell (WBC) counts and increased risk of infection
  • low platelet counts (thrombocytopenia)

Platelets are small blood cells responsible for helping your blood clot, such as in the case of an injury. When your platelet counts are too low, you may experience excessive bleeding.

Learn more about the link between lupus and low platelet counts, including possible symptoms, treatment options, and what you can expect in the long term.

Like other autoimmune diseases, lupus causes your immune system to attack cells and tissues in your body. The exact reason for this isn’t known, but experts think that genetic and environmental factors may play roles in lupus development.

The effects of lupus are systemic, meaning it affects various tissues and cells throughout the body. As your condition progresses, it may also affect your blood cells, including platelets.

Thrombocytopenia occurs when you have lower blood platelets than what is considered typical. A typical count ranges between 150,000 and 450,000 platelets per microliter of a blood sample. The lower the count drops, the higher your risk of bleeding.

While about 20%–40% of people with lupus develop low blood platelet counts, most of these cases aren’t severe.

When you have lupus, you may be at an increased risk of developing thrombocytopenia from your immune system attacking otherwise healthy platelets.

Some lupus medications may also increase your risk of thrombocytopenia. These include:

Not everyone with lupus has low platelets, though. Thrombocytopenia has other causes aside from autoimmune diseases. These include:

  • difficulties with your spleen or bone marrow
  • recent surgeries or infections
  • cancer

Thrombocytopenia, with or without lupus, doesn’t always cause symptoms, especially in mild cases. But, when symptoms do occur, they may include:

  • easy bruising or bleeding
  • small, pinpoint-shaped red to purple spots on your skin (petechiae)
  • bruise-like spots on your skin that can range in color from red to yellow or brown (purpura)
  • frequent nosebleeds
  • bleeding gums, especially after flossing or brushing your teeth
  • bleeding that doesn’t stop easily after minor injuries
  • heavy menstruation
  • blood in your urine
  • bloody stools
  • excessive fatigue

For some people, symptoms of low platelet counts may also be the first signs of lupus. According to a 2017 study, as many as 16% of people with lupus had thrombocytopenia months or years before receiving a lupus diagnosis.

Doctors rely on both a physical exam and blood testing to determine if you have thrombocytopenia in lupus. They’ll ask you about any bleeding-related symptoms and look for signs of easy bleeding and bruising on your skin.

A doctor can measure your platelet count via a complete blood count (CBC). They may also order a blood smear. This involves a laboratory examination of a sample of your blood under a microscope to look for the number and size of your platelets.

According to the Lupus Foundation of America, mild thrombocytopenia usually doesn’t require treatment. But, a doctor may consider the following treatments for more severe cases:

According to a 2017 research review, thrombocytopenia can worsen your outlook with lupus. Some studies link thrombocytopenia to a higher risk of death.

Research also links low platelet counts to a more severe course of lupus. People with lupus and low platelets also tend to experience:

Severely low platelet counts may increase your risk of spontaneous or severe bleeding, which may be fatal.

But your outlook depends on the severity of both your lupus and thrombocytopenia. Treatment with immunosuppressants can often manage mild cases of lupus thrombocytopenia.

If you or a loved one has lupus and are concerned about low platelets, consider the following pieces of information to discuss further with a doctor.

Does a low platelet count in lupus mean I should avoid certain activities?

Not all cases of thrombocytopenia are severe enough to warrant avoiding certain activities. In some cases, bleeding can also be spontaneous, meaning it happens without any obvious injury.

But, if your platelet counts are extremely low, a doctor may recommend refraining from contact sports and other activities that could result in injuries. Doing so can help prevent excessive bleeding.

What autoimmune diseases cause low platelets?

Low blood platelets may be due to lupus and other autoimmune diseases like rheumatoid arthritis.

Immune thrombocytopenia, aka idiopathic thrombocytopenic purpura (ITP), is another autoimmune disease in which the cause of low blood platelets may be unrelated to another condition (idiopathic).

According to one 2022 retrospective study, ITP may be a risk factor for developing lupus.

What would a CBC look like with lupus?

A CBC measures all of your blood cells. With lupus, you may have lower than typical RBC, WBC, and platelet counts. A doctor may diagnose lupus thrombocytopenia if your platelet count is lower than 150,000 per microliter.

Lupus can affect multiple systems in your body, including your blood cells. With lupus, it’s possible to have low RBC, WBC, and platelet counts. You may develop thrombocytopenia if your platelets drop to lower-than-typical levels.

For most people with lupus, low platelet counts aren’t serious. You can treat the condition with some of the same medications you take for lupus. But, severe thrombocytopenia can be life threatening for some people due to excessive bleeding.

If you’re concerned about your platelet count and are experiencing symptoms of thrombocytopenia, consider talking with a doctor about possible treatments.