The spleen is an organ situated in the upper left side of the abdomen, underneath the ribcage. It plays a significant role in the lymphatic and immune systems, filtering blood, removing old or damaged blood cells, and producing white blood cells and antibodies. Splenomegaly is the medical term for an enlarged spleen, a condition where the organ swells beyond its normal size. This enlargement is always a sign of an underlying illness and can indeed lead to symptoms like nausea.
How Splenomegaly Causes Nausea
An enlarged spleen can cause gastrointestinal symptoms, including nausea, due to its location next to other digestive organs. The spleen normally rests adjacent to the stomach, the colon, and the left kidney. When the spleen becomes enlarged, it physically expands into the surrounding abdominal space.
This expansion results in the spleen pressing against neighboring structures, most notably the stomach. Compression of the stomach by the swollen spleen can reduce the stomach’s capacity. This mechanical pressure leads to a feeling of fullness after eating only a small amount of food, a symptom known as early satiety.
The sensation of early satiety and abdominal discomfort can trigger feelings of nausea. Although the spleen does not directly control digestion, its physical impingement on the stomach interrupts the normal process of eating and gastric emptying. This effect is a direct mechanical consequence of the spleen’s increased size.
Recognizing Other Symptoms of Spleen Enlargement
While nausea and early satiety are often present, an enlarged spleen frequently causes other symptoms in the upper left abdomen. Many people experience pain or discomfort in this region, resulting from the stretching of the organ’s outer capsule due to swelling. This pain may sometimes extend and be felt in the left shoulder, which is known as referred pain.
Individuals with splenomegaly often experience unexplained fatigue. This tiredness can be related to the increased workload of the enlarged spleen or be a symptom of the underlying condition. Furthermore, an overactive spleen can trap and destroy too many red blood cells, white blood cells, and platelets. This process contributes to anemia and low cell counts, causing generalized weakness.
Common Underlying Causes of Splenomegaly
Splenomegaly is a symptom, not a standalone disease, caused by a wide range of underlying medical conditions that affect the spleen’s function. These causes are generally categorized into three main groups based on the mechanism of enlargement.
Infections
Infections frequently cause the spleen to enlarge due to an increased immune response. Viral infections, such as mononucleosis, and bacterial infections, like endocarditis, force the spleen to increase the production of immune cells, causing it to swell. Parasitic infections, such as malaria, are also a common cause of splenomegaly, particularly in certain regions of the world.
Liver Diseases
Liver diseases represent another category, primarily through a process called portal hypertension. Conditions like cirrhosis cause scarring in the liver, which increases pressure in the portal vein system connected to the spleen. This high pressure causes blood to pool and back up in the spleen, leading to congestion and enlargement.
Blood Cell Disorders and Cancers
Blood cell disorders and cancers can cause splenomegaly through infiltration or excessive destruction of blood cells. Blood cancers like leukemias and lymphomas can infiltrate the spleen with abnormal cells, causing it to expand. Certain types of anemia, where red blood cells are destroyed prematurely, also force the spleen to work harder to filter these cells, leading to enlargement.
Diagnosis and Medical Management
The diagnosis of an enlarged spleen often begins with a physical examination. A healthcare provider gently palpates the abdomen to feel for the organ below the left ribcage. Since a normal spleen is usually not palpable, feeling a distinct mass suggests enlargement.
To confirm the diagnosis and assess the degree of enlargement, imaging studies are commonly used. An abdominal ultrasound or a CT scan can accurately measure the spleen’s size and determine if it is pressing on other organs. Blood tests, including a complete blood count, are also performed to look for abnormalities in cell counts, which provide clues about the underlying cause.
The management of splenomegaly focuses on treating the disease responsible for the enlargement. If a bacterial infection is the cause, antibiotics will be administered to resolve the infection and allow the spleen to return to its normal size. Management of liver disease or treatment of a blood cancer will be initiated to address those specific conditions. In rare instances where the enlarged spleen causes severe complications, such as life-threatening blood cell destruction or significant pain, surgical removal of the spleen (splenectomy) may be considered.