Bulging eyes is the abnormal protrusion (bulging out) of one or both eyeballs.

Prominent eyes may be a family trait. However, prominent eyes are not the same as bulging eyes. Bulging eyes should receive immediate attention.

Bulging of a single eye, especially in a child, is a very serious sign and should be evaluated immediately.

Hyperthyroidism (particularly Graves disease) is probably the most common cause of bulging eyes. With this condition, the eyes don't blink very often and seem to have a staring quality.

Generally, there should be no visible white between the top of the iris (the colored part of the eye) and the upper eyelid. Seeing white in this area is usually a good indication that the eye bulging is abnormal.

Because eye changes develop slowly, family members may not notice it until the condition is relatively advanced. Photographs often draw attention to the bulging when it may have gone unnoticed previously.

• Glaucoma
• Graves disease
• Hemangioma
• Histiocytosis
• Hyperthyroidism
• Hyperthyroidism caused by medications for other conditions
• Leukemia
• Neuroblastoma
• Orbital cellulitis or periorbital cellulitis
• Rhabdomyosarcoma

The underlying cause of this symptom needs to be treated by a health care provider. Because bulging eyes can cause a person to be self-conscious, emotional support is important.