What Does the Spleen Do? Function, Location, and Role in the Body

Aug 22, 2019

Ask people to explain what the stomach does, and most everyone will have a good answer. Try to get them to describe the role of the spleen, and it may be a different story. At the top of the list of organs that are a mystery to many, a healthy spleen quietly goes about its very important job of keeping your blood healthy and your immune system functioning.

If the spleen becomes damaged, however, you could find yourself in immense amounts of pain or at a greater risk of infection. It is even possible that a laceration or rupture of your spleen could cause life-threatening internal bleeding. Fortunately, if you have a damaged or enlarged spleen, it can be removed. You can live a relatively normal, healthy life without a spleen, though you will have to be more cautious about infections, as your immune system relies on the spleen to work effectively.

What Does the Spleen Do?

Hidden between the 10th and 11th ribs at the bottom of the left side of the rib cage, your spleen is roughly the size of your fist. The spleen is by no means the largest organ in your abdomen, but it is the largest member of your lymphatic system. Despite its location near the digestive tract, and having vascular connections to both the pancreas and stomach, the spleen is not directly involved in digestion.

Like an oil filter in your car, the spleen cleans your blood as it flows through it. By removing old or damaged red blood cells and adding white blood cells to your bloodstream to respond to infections, the spleen helps keep your immune system functioning. The spleen also works as a recycling center. Healthy red blood cells have a lifespan of only 120 days, and your body uses the passages in the spleen to capture these old cells and break them down to reuse the iron they contain.

Your spleen is responsible for keeping your blood supplied with healthy red blood cells and with various types of white blood cells like lymphocytes that are necessary in fighting off infections. In addition to producing these disease fighting cells, the spleen can also store them for rapid deployment when the body detects an immune response is necessary. Look inside your spleen and you will find two kinds of tissue, white pulp and red pulp, hiding inside a tough layer of connective tissue called the capsule.

Red pulp is primarily responsible for filtering blood and holding reserves of macrophages and a type of white blood cells called monocytes. In the event of tissue injury such as a heart attack, the spleen releases these monocytes into the bloodstream. Upon reaching the site of injury, monocytes help manage inflammation and promote tissue healing.

White pulp is the smaller part, making up only a quarter of the spleen, though you gain more white pulp as you age. White pulp in the spleen is similar to the tissue in your lymph nodes, and is responsible for creating the plasma cells and macrophages your body uses to attack invading microorganisms.

Diseases Affecting the Spleen

When the spleen is diseased or damaged, it will often begin to enlarge in a condition called splenomegaly. Various conditions can cause an enlarged spleen, as blood flow through the spleen can be interrupted by many different diseases and infections. Many of these conditions will cause blood to pool in the spleen rather than flow through it, causing the spleen to swell.

Unlike diseases where a specific symptoms lead to an easy diagnosis, the underlying condition causing a splenomegaly is harder to determine. Everything from hereditary blood disorders and cancer to infections like mononucleosis (mono) can impair the function of the spleen. Diagnosis can be difficult, as even an enlarged spleen may not be immediately detectable in a physical examination.

Asplenia is a term used when someone has had their spleen removed during a splenectomy, or if a condition like sickle cell disease has caused your spleen to stop functioning early in life. In these cases, the outcome is the same; the lack of splenic function means your immune system cannot function optimally and you may be at a greater risk for certain kinds of infections.

Splenic Infarction results when blood flow to the spleen is cut off or reduced. One common cause is a blood clot or blockage of the splenic artery, but this is not the only way blood flow to the spleen is interrupted. Cancer, complications of valvular heart disease, heart attacks and conditions like sickle cell disease can all result in splenic infarction.

Closely related to this condition is splenic abscess. This rare infection can result as a complication of pneumonia or gastric disorders like bowel perforation. Both infarction and abscess can cause a similar range of symptoms. Pain in left side of the abdomen is common, and pain can extend into the chest and left shoulder. Fever and vomiting are also possible.

Sickle cell disease, where red blood cells take on a different shape than usual can lead to many issues, including hemolytic anemia and hyposplenism, which can increase the risk of infection. The size of blood vessels in the spleen allows for healthy blood cells to pass through, while damaged cells are filtered out. The difference between healthy and unhealthy blood cells is measured in microns, which means any change in the shape of your blood cells can affect the ability of your spleen to function.

With the central role the spleen plays in cleaning and managing the health of your blood, the spleen can be affected by diseases of other organs. Liver disease like cirrhosis can cause the red pulp of the liver to swell, leading to splenomegaly. Syphilis, tuberculosis, endocarditis are begin in other parts of they body, but can affect the spleen.

Infectious diseases like malaria can also damage the spleen. If you contract malaria for the first time, your spleen may become enlarged, though after multiple exposures to malaria it is possible that a splenic infarction could occur, causing the spleen to shrink rather than becoming larger.

The amount of extra blood held in the spleen can make splenic injuries dangerous or even life-threatening. With its location near the ribs, the spleen is usually well protected, but it can be susceptible to physical trauma. If you break your ribs in a car accident, or while participating in contact sports, the ribs can be pushed into the spleen, possibly breaking the capsule of the spleen. When the capsule of the spleen is ruptured, large amounts of internal bleeding can occur. Without immediate medical treatment, it is possible to bleed to death from a lacerated or ruptured spleen.

Can You Live Without a Spleen?

In some cases, either from disease or physical trauma, your spleen may need to be removed. This procedure, referred to as a splenectomy, can be done through a series of small incisions in a laparoscopy, or sometimes it is removed through a single, larger incision. Like any abdominal surgery, there is a risk of infection, though the removal of the spleen carries an extra twist. Given the role the spleen plays in helping your body fight infection, having it removed means you are at a greater risk for infection for the rest of your life.

Life after a splenectomy can often continue on as usual. You will need to be careful about your health, and take precautions knowing your immune system may not work as effectively as it once did. Your doctor will likely prescribe a series of vaccines to help fortify you against certain types of influenza, pneumonia and other infections, and may even suggest taking preventative antibiotics.

When to Seek Medical Attention

Common sense should be your guide with visiting your doctor for any medical condition. If you are experiencing a fever, vomiting, intense abdominal and chest pain, seeking medical attention is advised. If your pain is centered in the upper left quadrant of your abdomen, or if you are feeling full even when you haven't eaten anything, you may have a splenomegaly.

Your doctor will begin with a physical examination, and will likely order blood tests to see if your spleen is functioning normally. Since an enlarged spleen is difficult to detect in a physical exam, imaging such as an X-ray or CT scan may be necessary to help diagnose the underlying condition causing your symptoms. Due to the amount of vascular tissue in your spleen, it is unlikely your doctor will order a biopsy of the spleen itself. A biopsy of bone marrow or lymph node biopsy can sometimes be used to determine if spleen removal is necessary. Serious signs of a splenic disorder are frequent bleeding, anemia and fatigue. Remember that sudden severe pain, heavy bleeding, could be an emergency situation. Always differentiate between chronic symptoms and sudden symptoms, which should be seen in an ER.

If you are experiencing chronic symptoms as described, as well as pain in the abdomen, chest and shoulder, make an appointment at Carolina Digestive Health Associates. The causes of splenic disorder can vary, and diagnosing your condition properly can take time. The sooner you begin searching for the cause, the faster you will be on the road back to health.