Yellowing of the whites of the eyes, medically termed scleral icterus or jaundice, is generally a sign of an underlying health issue. The perception that a “little yellow” is normal is misleading, as this discoloration indicates a measurable buildup of a specific substance in the bloodstream. When the sclera turns yellow, it signals that the body’s internal processes for waste management are struggling. This symptom warrants medical attention to determine the cause, which can range from minor conditions to serious organ dysfunction.
The Mechanism Behind Yellowing
The yellow color that appears in the eyes and skin is caused by the accumulation of a compound called bilirubin. Bilirubin is a yellowish waste product created when the body recycles old or damaged red blood cells. It forms during the breakdown of hemoglobin. Under normal circumstances, the liver filters this bilirubin from the bloodstream and chemically modifies it. The modified bilirubin then becomes a component of bile, which is secreted into the digestive tract and ultimately removed from the body, primarily in stool. When this process is interrupted, bilirubin builds up in the blood (hyperbilirubinemia). Scleral icterus becomes visually noticeable when the bilirubin concentration in the blood exceeds approximately 3 milligrams per deciliter.
Primary Causes of Jaundice
The majority of true jaundice cases are linked to problems occurring either within the liver itself or in the structures responsible for draining it. Viral hepatitis, caused by infections like Hepatitis A, B, or C, leads to inflammation and damage of liver cells. This cellular injury impairs the liver’s ability to efficiently process and excrete bilirubin, causing it to back up into the circulatory system. Chronic conditions such as cirrhosis, which involves long-term scarring of the liver tissue, also compromise the organ’s filtering capacity. Another significant group of causes involves obstruction of the bile ducts. Blockages commonly occur due to gallstones, or tumors in the pancreas or bile ducts that physically compress these drainage pathways.
Other Conditions That Cause Scleral Yellowing
Not all yellowing of the eyes points directly to liver failure, as disruptions can also occur before the liver is even involved. One category is pre-hepatic jaundice, which results from an excessive, rapid breakdown of red blood cells, overwhelming the liver’s capacity to process the resulting bilirubin. This phenomenon occurs in conditions like hemolytic anemia, where red blood cells are destroyed prematurely. The sheer volume of bilirubin produced exceeds the liver’s filtering rate, leading to its accumulation.
Gilbert’s Syndrome
A more benign, inherited cause of intermittent yellowing is Gilbert’s Syndrome, a common genetic disorder affecting a small percentage of the population. Individuals with this syndrome have a reduced level of a specific liver enzyme needed to chemically modify bilirubin. This results in mildly elevated bilirubin levels, often noticeable during periods of stress, fasting, or illness, but it is generally a harmless, chronic condition.
Non-Jaundice Growths
Furthermore, some non-jaundice eye growths, such as pinguecula or pterygium, can appear yellowish due to deposits of fat and protein on the conjunctiva, which is often mistaken for scleral icterus.
When to See a Doctor Immediately
While any persistent yellowing should prompt a doctor’s visit, certain accompanying symptoms indicate a potentially life-threatening medical emergency. The sudden onset of yellow eyes combined with a high fever and chills can suggest a serious infection in the bile ducts or liver, which requires immediate attention. Severe abdominal pain, particularly localized in the upper right quadrant of the abdomen, may signal acute inflammation or a complete blockage that needs urgent surgical intervention. A change in waste products is another warning sign, including the presence of very dark urine and stools that are unusually pale or clay-colored. These changes suggest that bilirubin is being excreted through the urine instead of the digestive tract due to an obstruction. Finally, any rapid changes in mental status, such as confusion, severe drowsiness, or disorientation, can indicate hepatic encephalopathy, where toxins are building up and affecting brain function.