Enlarged Spleen: Causes, Symptoms, and Treatments

Medically Reviewed by Jabeen Begum, MD on March 05, 2024
5 min read

Your spleen sits under your rib cage in the upper left part of your abdomen toward your back. This organ helps filter your blood, trapping old and damaged red blood cells. It also contains white blood cells, which are an important part of your immune system and help fight off infections.


A spleen is normally about the size of your fist. A doctor usually can't feel it during an exam. But infections and injuries can cause it to swell and become larger. Many health conditions can cause an enlarged spleen (splenomegaly). Your doctor will need to do examinations to figure out the cause and treatment.

An enlarged spleen can be caused by infections, liver diseases such as cirrhosis, blood diseases that cause abnormal blood cells, problems with the lymph system, or other conditions.

Here are some common causes of an enlarged spleen:


  • Viral infections, such as mononucleosis
  • Parasitic infections, such as toxoplasmosis
  • Bacterial infections, such as endocarditis (an infection of your heart's valves)


Other causes of an enlarged spleen include:

  • Inflammatory diseases such as sarcoidosis, lupus, and rheumatoid arthritis
  • Trauma, such as contact sports injuries
  • Cancer that has spread (metastasized) to the spleen
  • A cyst -- a noncancerous fluid-filled sac
  • A large abscess -- a pus-filled cavity usually caused by a bacterial infection
  • Diseases that affect your metabolic system (such as Gaucher disease and amyloidosis ), which can cause substances to collect in your blood and organs
  • Thrombosis, in which a blood clot blocks a blood vessel in the spleen
  • Heart failure
  • Portal hypertension, which is high blood pressure in a vein in your belly that connects to your spleen and other organs

Most people don't know they have an enlarged spleen because symptoms are rare. People usually find out about it during a physical exam.

If you do have symptoms, you might:

  • Have a low appetite or feel full after eating very little
  • Feel discomfort, fullness, or pain on the upper left side of your belly (the pain may spread to your left shoulder )

If your spleen starts to have problems functioning, you might have symptoms of anemia, which is low levels of iron in your blood. Fatigue and weakness are common signs of anemia. You might also bleed or bruise more easily. And you might get infections such as colds more often.

Your doctor will ask you questions and do a physical exam to diagnose an enlarged, painful spleen. This involves palpating (examining by touch) your spleen. You will also likely need tests to confirm the cause of your swollen spleen, such as:

  • Blood tests to check blood cell count and see how your liver is working
  • An ultrasound or CT scan to see the size of your spleen and whether it's getting too close to other organs
  • An MRI to see how blood is flowing through your spleen

It's important to seek treatment for the cause of your enlarged spleen. Left untreated, an enlarged spleen can lead to serious complications. In most cases, treatment of the underlying cause can prevent the removal of the spleen.

If your doctor can't find the cause of your enlarged spleen, or if the condition that's causing it can't be cured, you might need to have it removed in a surgery called a splenectomy. Another option your doctor may choose is to treat it with low-dose radiation therapy. This uses energy beams to shrink your spleen.

Splenectomy complications

If your spleen is removed, it's harder for your body to remove bad bacteria. This makes it easier for you to get an infection, so your doctor may give you vaccines or other medications to help protect you. Your doctor will also suggest you wear a medical ID bracelet to let other medical professionals know that you have had your spleen removed.

Getting treatment for an enlarged spleen quickly can prevent some of these complications:

  • Tissue death: If your spleen gets very large, your blood vessels might not be able to supply enough blood to keep the tissues alive.
  • Hypersplenism: A very large spleen can become overactive. When this happens it might remove too many blood cells from your body, which can cause anemia -- a condition in which you don't have enough red blood cells. It can also lower your levels of white blood cells (which are important for your immune system) and platelets (which help your blood clot).
  • Rupture: If your spleen gets too large, it could rupture or burst. This could happen suddenly, or it could be caused by an impact. A ruptured spleen can cause a lot of blood loss and be life-threatening.

An enlarged spleen can be caused by many underlying health conditions. It's important to get treatment quickly to prevent complications, such as a ruptured spleen. In most cases, your doctor can treat your enlarged spleen by treating the health condition causing it. In some cases, you might need surgery to remove your spleen. It's possible to live without a spleen, but you'll need extra immune protection with vaccines and antibiotics.

What does an enlarged spleen indicate?

It usually means that you have an illness that is affecting your spleen, causing it to swell. This is often because of an infection or cancer.

What is the most common cause of an enlarged spleen?

Bacterial, viral, and parasitic infections and cancer are the most common causes.

What can be done for an enlarged spleen?

Your doctor can treat the condition that's causing it. You might need surgery to remove it.

Can an enlarged spleen go back to normal size?

Yes, it can return to its normal size once the underlying condition is treated.