The spleen is a small, purple-colored organ, about the size of a fist, which is located in the left side of the abdomen . It usually measures up to 4 inches long  and weighs about 0.44 pounds .
It belongs to the lymphatic system, which functions as a protection against infections. It also maintains the balance of body fluids. The repair of old and damaged cells is also part of the spleen’s functions.
The spleen is located in the left hypochondriac region of the abdomen . It is specifically situated between the upper left portion of the stomach and the diaphragm. It is also inside the lower portion of the ribs; hence, this cannot be palpated unless it is enlarged. 
Picture 1: Spleen location
Image source: askdrjohnbergman.com
Spleen pain is a pain felt in the left side of the abdomen. The pain usually worsens during breathing and after eating large or heavy meals. However, this is difficult to diagnose, since pain in the abdomen may link to disorders in other nearby organs, such as the stomach. 
Spleen Pain Location
Aside from the left side of the abdomen, spleen pain may radiate towards other parts of the body, such as the shoulders, left side of the chest, back, and umbilicus. The pain rarely reaches the right side of the abdomen.
Spleen Pain Causes
The most common cause of spleen pain is an infection which may be bacterial, viral, or parasitic. It causes moderate to severe pain in the spleen . Examples of infections causing spleen pain and enlargement are as follows:
- Mononucleosis – the abnormal elevation of mononuclear monocyte levels in the blood caused by a viral infection, leading to fever and swollen lymph nodes
- Toxoplasmosis – a parasitic infection caused by Toxoplasma gondii, which is transmitted by cats
Syphilis – a bacterial infection caused by Treponema pallidum, which is usually transferred during sexual intercourse 
Splenomegaly refers to the enlargement of the spleen. This is a rare cause of spleen pain because the spleen is covered with an elastic capsule which allows the spleen to enlarge several times from its normal size without bursting or rupturing.
The pain caused by splenomegaly is only mild to moderate pain . Enlargement of the spleen can be caused by a bacterial, viral or parasitic infection, or by the following conditions:
- Hodgkin’s disease
- Niemann-Pick disease
- Portal hhypertension
- Gaucher’s disease
- Cystic fibrosis
- Felty syndrome
- Rheumatoid arthritis
- Biliary atresia
- Sclerosing cholangitis 
Picture 2: Splenomegaly
Image source: mycmllife.eu
Splenic infarct refers to the death of a tissue in a certain portion of the spleen. It is caused by an obstruction in the splenic artery. Blood flow is therefore blocked, leading to ischemia or tissue damage because of lack of oxygen.An embolus is one of the most common examples of blood flow obstruction in the spleen. It is usually asymptomatic in mild cases.
In moderate to severe cases, the symptoms include the following:
- Chest pain
- Left upper quadrant pain
- Left shoulder pain 
Splenic rupture is an emergency condition involving the destruction of the capsule of the spleen. When the spleen breaks open, blood pours out into the abdominal cavity, causing immense internal bleeding. This also causes severe abdominal pain. A ruptured spleen can be caused by a trauma or blow in the abdomen. The most common causes are the following:
- Vehicular accidents
- Bicycle accidents
- Injuries while playing sports such as hockey and football
- Violence or torture
It can also be caused by an underlying disease, such as malaria, mononucleosis, lymphoma, and hemolytic anemia. In these conditions, the spleen capsule becomes thin, making it more prone to damage during traumas and injuries. There are also claims that colonoscopy, a diagnostic procedure used to observe the large intestine, also increases the risk of rupturing the spleen. The symptoms of a ruptured spleen are the following:
- Severe abdominal pain
- Blurred vision
- Anxiety and restlessness 
Spleen rupture is diagnosed through a physical examination. The abdominal area is hard and swollen because of the blood that filled the area. A rapid heart rate and low blood pressure can also be observed because of the large amounts of blood lost.
The low blood pressure indicates that the patient needs immediate medical attention. Imaging tests are also done. The most common is the computerized tomography (CT) scan. However, this cannot be used in patients suffering from severe spleen rupture, and in patients allergic to contrast media. Thus, other imaging tests are done, such as the following:
- Magnetic resonance imaging (MRI)
- Diagnostic peritoneal lavage
- Focused abdominal sonographic technique 
Spleen Pain Treatment
- The most important treatment for spleen pain is splenectomy, especially when the pain is caused by a splenic infarct or a splenic rupture. Splenectomy refers to the removal of the whole spleen. If only a portion of the spleen is removed, it is referred to as partial splenectomy. However, unlike the liver, the portion of the spleen that is removed cannot regenerate. 
- Splenectomy is done using two methods: laparotomy or open surgery, and laparoscopy. In laparotomy, the spleen is removed through a single incision in the abdomen. The incision is made on the left side of the abdomen, right under the rib area. Before removing the spleen, it is disconnected first from the blood supply and from the pancreas. After it is removed, the incision is closed using sutures and stitches. 
- Laparoscopy, on the other hand, is a less invasive procedure involving three or four small holes in the abdomen. Through these holes, the laparoscope and other medical instruments are inserted. The whole procedure is observed through a monitor connected to the laparoscope. However, this procedure cannot be used in swollen and very large spleens. It also cannot be used in obese patients, or in patients who have scars in the spleen tissue caused by a previous operation. 
Picture 3: Splenectomy
Image source: jacksonregionalsurgery.com
When the spleen is removed, the body becomes more prone to infections. Hence, vaccinations become necessary. Vaccines usually given include meningococcal vaccine, pneumococcal vaccine, and vaccine against Haemophilus influenzae type B. Antibiotics are also prescribed to prevent contracting infections. It is also advised that the patients must not go to malaria-infected areas.