Enlarged spleen (splenomegaly)
Your spleen is a small organ located just below your rib cage on your left side. Normally, your
spleen is about the size of a fist, but a number of conditions — from infections to liver disease
and some cancers — can cause an enlarged spleen, also known as splenomegaly (spleh-no-MEGuh-lee).
Most people don't have symptoms with an enlarged spleen. The problem is often discovered
during a routine physical exam. Your doctor won't be able to feel a normal-sized spleen —
unless you're very slender — but can feel an enlarged spleen.
Treatment for an enlarged spleen focuses on relieving the underlying condition. Although
surgically removing an enlarged spleen isn't a first choice, it may be an option for you in certain
situations.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Symptoms
An enlarged spleen may cause:
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No symptoms, in some cases
Pain or fullness in the left upper abdomen that may spread to the left shoulder
Feeling full without eating or after eating only a small amount — this can occur when an
enlarged spleen presses on your stomach
Anemia
Fatigue
Frequent infections
Easy bleeding
When to see a doctor
See your doctor promptly if you have pain in your left upper abdomen, especially if it's severe or
the pain gets worse when you take a deep breath.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Causes
A number of infections and diseases can contribute to an enlarged spleen. The effects on your
spleen may be only temporary, depending on how well your treatment works. Contributing
factors include:
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Viral infections, such as mononucleosis
Bacterial infections, such as syphilis or an infection of your heart's inner lining
(endocarditis)
Parasitic infections, such as malaria
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Cirrhosis and other diseases affecting the liver
Various types of hemolytic anemia — a condition characterized by premature destruction
of red blood cells
Blood cancers, such as leukemia, and lymphomas, such as Hodgkin's disease
Metabolic disorders, such as Gaucher's disease and Niemann-Pick disease
Pressure on the veins in the spleen or liver or a blood clot in these veins
How the spleen works
Your spleen is tucked under your rib cage next to your stomach on the left side of your abdomen.
It's a soft, spongy organ that performs several critical jobs and can be easily damaged. Among
other things, your spleen:
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Filters out and destroys old and damaged blood cells
Plays a key role in preventing infection by producing white blood cells called
lymphocytes and acting as a first line of defense against invading pathogens
Stores red blood cells and platelets, the cells that help your blood clot
May act as an intermediary between your immune system and your brain, leading
researchers to speculate that they may one day be able to trigger the spleen's infectionfighting abilities by manipulating the nervous system
An enlarged spleen affects each of these vital functions. For instance, as your spleen grows
larger, it begins to filter normal red blood cells as well as abnormal ones, reducing the number of
healthy cells in your bloodstream. It also traps too many platelets. Eventually, excess red blood
cells and platelets can clog your spleen, interfering with its normal functioning. An enlarged
spleen may even outgrow its own blood supply, which can damage or destroy sections of the
organ.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Risk factors
Anyone can develop an enlarged spleen at any age, but certain groups are at higher risk,
including:
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Children and young adults with infections such as mononucleosis
People of African descent, who may develop splenomegaly as a complication of sickle
cell disease, a genetic blood disorder
People of Ashkenazi Jewish ancestry, who are at higher risk of Gaucher's disease,
Niemann-Pick disease and several other inherited metabolic disorders affecting the liver
and spleen
Travelers to areas where malaria is endemic
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Complications
Potential complications of an enlarged spleen are:
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Infection. Because an enlarged spleen can reduce the number of healthy red blood cells,
platelets and white cells in your bloodstream, you may develop frequent infections.
Anemia and increased bleeding also are possible.
Ruptured spleen. Even healthy spleens are soft and easily damaged, especially in car
crashes. When your spleen is enlarged, the possibility of rupture is far greater. A ruptured
spleen can cause life-threatening bleeding into your abdominal cavity.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Tests and diagnosis
An enlarged spleen is usually detected during a physical exam. Your doctor can often feel the
enlargement by gently examining your left upper abdomen, just under your rib cage. However, in
some people — especially those who are slender — a healthy, normal-sized spleen can
sometimes be felt during an exam.
Your doctor may confirm the diagnosis of an enlarged spleen with one or more of these tests:
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Blood tests, such as a complete blood count to check the number of red blood cells, white
blood cells and platelets in your system
Ultrasound or computerized tomography (CT) scan to help determine the size of your
spleen and whether it's crowding other organs
Magnetic resonance imagining (MRI) to trace blood flow through the spleen
Imaging tests aren't always needed to diagnose an enlarged spleen. But if your doctor
recommends imaging, you generally don't need any special preparation for an ultrasound or
MRI. If you're having a CT scan, however, you may need to refrain from eating before the test. If
you need to prepare, your doctor will let you know well in advance.
Finding the cause
Sometimes you may need further testing to identify what's causing an enlarged spleen, including
liver function tests and a bone marrow exam, which can give more detailed information about
your blood cells than can blood drawn from a vein.
In some cases, a sample of solid bone marrow is removed in a procedure called a bone marrow
biopsy. Or, you may have a bone marrow aspiration, which removes the liquid portion of your
marrow. In many cases, both procedures are performed at the same time (bone marrow exam).
Both the liquid and solid bone marrow samples are frequently taken from the same place on the
back of one of your hipbones. A needle is inserted into the bone through an incision. Because
bone marrow tests cause discomfort, you'll receive either general or local anesthesia before the
test.
Because of the risk of bleeding, a needle biopsy of the spleen is almost never done.
Occasionally, when there's no explanation for an enlarged spleen despite a thorough
investigation for a cause, your doctor may recommend surgery to remove your spleen. After
surgical removal, the spleen is examined under a microscope to check for possible lymphoma of
the spleen.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Treatments and drugs
If an enlarged spleen causes serious complications or the underlying problem can't be identified
or treated, surgical removal of your spleen (splenectomy) may be an option. In fact, in chronic or
critical cases, surgery may offer the best hope for recovery.
But elective spleen removal requires careful consideration. You can live an active life without a
spleen, but you're more likely to contract serious or even life-threatening infections, including
overwhelming post-splenectomy infection, which can occur soon after the operation. Sometimes,
radiation can shrink your spleen so that you can avoid surgery.
Reducing infection risk after surgery
If you do have your spleen removed, certain steps can help reduce your risk of infection,
including:
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A series of vaccinations both before and after the splenectomy. These include the
pneumococcal (Pneumovax), meningococcal and haemophilus influenzae type b (Hib)
vaccines, which protect against pneumonia, meningitis, and infections of the blood, bones
and joints.
Taking penicillin or other antibiotics after your operation and anytime you or your doctor
suspects the possibility of an infection.
Avoiding travel to parts of the world where diseases such as malaria are endemic.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).
Lifestyle and home remedies
If you have an enlarged spleen, avoid contact sports — such as soccer, football and hockey —
and limit other activities as recommended by your doctor. Modifying your activities can reduce
the risk of a ruptured spleen.
It's also important to wear a seat belt. If you're in an accident, a seat belt can help prevent injury
to your spleen.
Finally, be sure to keep your vaccinations up to date.
©1998-2013 Mayo Foundation for Medical Education and Research (MFMER).