What makes your platelets go down? Causes and conditions

October 1, 2025 •

3 min read

According to the National Heart, Lung, and Blood Institute, a low platelet count, known as thrombocytopenia, can result from various health conditions, medications, or lifestyle factors. It is crucial to understand these underlying issues to know what makes your platelets go down.

Quick Summary

A low platelet count, or thrombocytopenia, occurs when the body's bone marrow produces too few platelets, or platelets are destroyed or trapped faster than they can be replaced, often triggered by autoimmune diseases, infections, certain medications, or an enlarged spleen.

Key Points

Decreased Production: Low platelet counts can stem from issues in the bone marrow, where platelets are produced, often caused by cancers like leukemia, chemotherapy, or certain viral infections.
Increased Destruction: The body may destroy or use up platelets faster than they can be made, a process triggered by autoimmune disorders like lupus, severe infections, or reactions to some medications.
Splenic Trapping: An enlarged spleen, often resulting from liver disease or other conditions, can trap and hold too many platelets, reducing the number circulating in the blood.
Medication Impact: Certain drugs, including some over-the-counter pain relievers and blood thinners like heparin, can contribute to lower platelet counts.
Lifestyle Factors: Heavy alcohol consumption and nutritional deficiencies (like vitamin B12 and folate) can suppress the bone marrow's ability to produce platelets.
Professional Diagnosis is Key: Due to the wide range of potential causes, it is essential to consult a healthcare provider for an accurate diagnosis and appropriate treatment plan for low platelets.

Understanding Thrombocytopenia: An Overview

Platelets, also known as thrombocytes, are essential blood cells for clotting and preventing excessive bleeding. When their count drops below the normal range, it's called thrombocytopenia. This condition arises from three primary issues: reduced production in the bone marrow, increased destruction or usage of platelets, or platelets becoming trapped in the spleen.

Decreased Platelet Production in the Bone Marrow

The bone marrow is responsible for producing platelets. When it's not functioning correctly, fewer platelets are made. Causes include blood cancers like leukemia and lymphoma, which interfere with platelet-producing cells, and aplastic anemia, where the marrow doesn't produce enough blood cells. Viral infections such as HIV or hepatitis C can also temporarily slow bone marrow function. Cancer treatments like chemotherapy and radiation often damage bone marrow cells, leading to low platelets. Heavy alcohol use, exposure to toxic chemicals, and deficiencies in vitamin B12 and folate can also hinder platelet production.

Increased Platelet Destruction or Consumption

Sometimes, platelets are produced sufficiently but are then destroyed or used up too quickly. This can happen with autoimmune disorders like immune thrombocytopenia (ITP) and lupus, where the immune system attacks platelets. Severe bacterial or viral infections can also lead to inflammation and platelet destruction. Certain medications can trigger an immune response that destroys platelets, including some antibiotics and heparin. Pregnancy can sometimes cause mild, temporary thrombocytopenia. Blood clotting disorders like thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC) rapidly consume platelets through widespread clotting.

Spleen Trapping Platelets

The spleen filters blood and stores some platelets. If it becomes enlarged due to conditions like severe liver disease or certain cancers, it can trap too many platelets, reducing the number in circulation.

Comparing the Causes of Low Platelet Count

The table below outlines the key differences between the main reasons for thrombocytopenia:


Feature	Decreased Production	Increased Destruction	Spleen Sequestration
Primary Location of Issue	Bone Marrow	Bloodstream and Immune System	Spleen
Common Causes	Leukemia, chemotherapy, aplastic anemia, heavy alcohol use, viral infections, nutrient deficiencies, toxic exposure	Autoimmune diseases (Lupus, ITP), severe infections (sepsis), certain medications, pregnancy, TTP/DIC	Liver disease, blood cancers (leading to enlarged spleen)
Onset	Can be gradual or rapid, depending on cause	Can be sudden or chronic	Gradual, associated with underlying splenomegaly
Treatment Focus	Addressing the bone marrow dysfunction (e.g., treating cancer, correcting deficiencies)	Modulating the immune response, stopping offending medication, treating infection	Managing the underlying condition causing the enlarged spleen
Example	A patient undergoing chemotherapy experiences a dip in their platelet count.	A patient with lupus develops antibodies that target their own platelets.	A patient with advanced liver cirrhosis has an enlarged spleen that traps platelets.

The Role of Medication and Lifestyle

Beyond medical conditions, medications like aspirin, ibuprofen, and heparin can affect platelet counts or function. Lifestyle factors such as heavy alcohol use, which can damage the liver and suppress bone marrow, also contribute.

Importance of Diagnosis and Medical Advice

Accurate diagnosis by a healthcare professional is crucial due to the varied causes of low platelets. They will use blood tests, medical history, and medication review to find the cause. Self-diagnosis is not advised. For more information, the National Heart, Lung, and Blood Institute (NHLBI) is a valuable resource.

Conclusion

Low platelet counts can signal various health issues, from temporary conditions to serious chronic diseases. The main culprits involve problems with platelet production, increased destruction, or trapping in the spleen. A medical evaluation is essential to identify the specific cause and get appropriate treatment. Understanding these causes and seeking professional advice is vital for managing this health concern.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional for diagnosis and treatment.

Frequently Asked Questions

One of the most common causes of low platelets (thrombocytopenia) is an autoimmune condition called Immune Thrombocytopenic Purpura (ITP), where the immune system mistakenly attacks and destroys platelets.

Yes, infections can cause low platelets. Severe bacterial infections, like sepsis, and certain viral infections, such as HIV and hepatitis C, can lead to the destruction of platelets.

Yes, heavy alcohol consumption can lead to lower platelet counts. It suppresses the production of platelets in the bone marrow and can contribute to nutritional deficiencies and liver damage, further affecting platelet levels.

Yes, many medications can cause a decrease in platelets, including certain antibiotics, anti-seizure drugs, and the blood thinner heparin. This can be due to an immune reaction or other effects on platelet production or function.

Yes, mild thrombocytopenia can occur in some pregnant women, most often late in the pregnancy. This condition is usually not serious and typically resolves shortly after delivery.

In autoimmune diseases like lupus or Immune Thrombocytopenic Purpura (ITP), the immune system's antibodies mistakenly identify platelets as foreign and destroy them. This leads to an increased rate of platelet destruction, causing the count to drop.

The spleen can cause low platelets by trapping them. If the spleen becomes enlarged due to an underlying condition like liver disease, it can sequester an excessive number of platelets, decreasing the number circulating in the bloodstream.