Tears are typically clear, slightly saline fluid that cleanses the eye, provides lubrication, and contains agents that fight infection. When tears unexpectedly present with a yellow color, it is an abnormal symptom suggesting an underlying issue, ranging from temporary external factors to serious systemic health conditions. Understanding the cause is the first step toward appropriate evaluation.
Understanding Normal Tear Composition
The clear appearance of normal tears is due to their composition, which is mostly water, along with electrolytes like sodium and potassium. Tears form a three-layered film over the eye, consisting of an outer lipid layer, a thick middle aqueous layer, and an inner mucin layer. Proteins, including antimicrobial enzymes such as lysozyme, are dissolved throughout the aqueous layer to protect the ocular surface. Any substance introduced into this finely balanced film, whether from the body’s internal systems or an external source, can change the fluid’s transparency or color.
Systemic Health Conditions Causing Yellow Tears
The most significant internal reason for yellowing of bodily fluids is a condition known as jaundice, which results from an excess of bilirubin in the bloodstream. Bilirubin is a yellowish pigment created when the body breaks down old red blood cells. Normally, the liver processes this pigment and excretes it through bile. When the liver is compromised or the bile ducts are blocked, the bilirubin accumulates in the blood, a state called hyperbilirubinemia, which can stain tissues.
This systemic buildup causes the whites of the eyes to turn yellow, a sign known as scleral icterus, and the pigment can also be secreted into the tear fluid. Conditions that impair the liver’s function, such as hepatitis, cirrhosis, or gallstones blocking the bile ducts, are primary causes of this pigment buildup. A less harmful, genetic condition called Gilbert’s syndrome also causes bilirubin levels to fluctuate, sometimes leading to mild, temporary yellowing.
Localized and External Sources of Tear Discoloration
Not all causes of yellow tears are systemic; many result from localized issues in the eye itself or external contamination. The most common localized cause is the presence of yellow or yellow-green eye discharge, often mistaken for tears, which results from a bacterial eye infection. This discharge, known as pus, is a mixture of mucus, dead white blood cells, and bacteria remnants that mixes with the clear tear fluid. Bacterial conjunctivitis (pink eye) frequently causes this sticky, yellow discharge, which can crust over the eyelids upon waking.
External factors can also temporarily give tears a yellow tint. For example, eye doctors routinely use sodium fluorescein dye during an eye examination to check for corneal abrasions or dry eye. This orange-yellow dye turns the tear film a bright yellow color before it is quickly washed away. Additionally, some oral medications, such as the antibiotic Rifampin, are known to secrete a yellow-orange pigment into all bodily fluids, including tears, sweat, and urine.
The Importance of Medical Consultation
The appearance of yellow tears or discharge should prompt a medical evaluation, regardless of the suspected cause. A healthcare professional, such as a general practitioner or an optometrist, can determine if the discoloration is localized to the eye or a manifestation of a systemic issue. Diagnosis for an eye infection typically involves a physical examination and possibly a swab of the discharge to identify the causative bacteria. If a systemic cause is suspected, the evaluation will likely include blood tests to measure bilirubin levels and assess liver function. Seeking professional advice ensures that a potentially serious underlying health condition is not overlooked and that appropriate treatment is started promptly.