Hypersplenism occurs when your spleen is abnormally enlarged and becomes overactive. An overactive spleen removes too many blood cells from your circulation, leaving you with fewer than you need.
Hypersplenism is when your spleen becomes overactive in doing its job. Its job is to filter out old and damaged cells from your bloodstream. When your spleen becomes overenthusiastic about filtering your blood, it removes too many blood cells too soon, leaving you with a deficit of blood cells (cytopenia).
Hypersplenism may lead to a deficit of certain types of blood cells or all of them. You might have:
Hypersplenism can be mild to severe, and so can the deficit of blood cells you’re left with. Some people won’t notice the effects of hypersplenism and may not need treatment for it. In other cases, it can be a significant factor in your overall health — especially when it occurs with a serious underlying disease.
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Hypersplenism occurs when your spleen becomes abnormally enlarged (splenomegaly). When your spleen enlarges, its blood volume increases. Your spleen retains a greater percentage of your total blood cells at one time. As it retains them, it filters and discards more of them, eventually even healthy ones.
Common causes of splenomegaly that may lead to hypersplenism include:
You may not notice symptoms with hypersplenism. If you do, you may have:
A healthcare provider will look for evidence of splenomegaly and measure your blood cell levels. They may be able to feel your swollen spleen during a physical exam. They may also take an ultrasound to confirm it. A complete blood count will tell them which types of blood cells you are low in, and how low.
Hypersplenism is usually a side effect and an indicator of another, more important condition. If you haven’t yet been diagnosed or aren’t yet receiving treatment for that condition, your healthcare provider will focus on that first. They may need to order additional tests to determine the cause.
Treatment for hypersplenism itself will depend on how severe it is. It may include:
Hypersplenism is treatable, but your prognosis will depend on your underlying condition. Some conditions are temporary, some are chronic (long-lasting) and some are progressive (long-lasting and worsening.) If hypersplenism causes cytopenia, you can restore your blood cell count with transfusion.
Hypersplenism is a side effect of splenomegaly. Splenomegaly is when your spleen is abnormally enlarged. Many things can cause your spleen to enlarge and to become overactive, but hypersplenism doesn’t always occur. All overactive spleens are enlarged, but not all enlarged spleens are overactive.
A note from Cleveland Clinic
Hypersplenism is first and foremost a symptom of another condition. You may have a disorder within your spleen itself, or it may originate somewhere else in your body. Because your spleen is involved in storing and filtering your blood, the diseases that affect it may involve your blood or blood vessels.
Treating hypersplenism usually means treating the underlying condition. This is often enough to restore normal function to your spleen. If your condition persists, you may need blood transfusions to help restore your blood cell count, or your provider may choose to treat your spleen directly.
Last reviewed by a Cleveland Clinic medical professional on 10/25/2022.
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