Eyes that bulge, or protrude out of their normal position, could be a sign of a serious medical condition. Proptosis and exophthalmos are the medical terms used to describe bulging eyes.

While some people are born with eyes that protrude more than normal, others develop them as a result of an underlying medical condition.

In most cases, the white part of your eye shouldn’t be visible above your iris (colored part of the eye) without lifting your eyelid.

If the white of your eye shows between your iris and your upper eyelid, it may be a sign of abnormal bulging. Your recommended treatment plan will depend on the underlying cause of your eye bulging.

Sudden bulging of only one eye is an emergency. Seek medical attention immediately. It may be a sign of a serious medical problem.

The most common cause of bulging eyes is hyperthyroidism, or an overactive thyroid gland. Your thyroid gland is located in the front of your neck. It releases several hormones that help control your metabolism.

Hyperthyroidism occurs when your thyroid releases too many of these hormones.

An autoimmune disorder called Graves’ disease is the most common cause of hyperthyroidism and bulging eyes. In this condition, tissues around your eye become inflamed. This creates the bulging effect.

Anyone can develop Graves’ disease. Women between the ages of 30 and 60 are most often affected, the Office on Women’s Health reports.

Other potential causes of bulging eyes include:

  • neuroblastoma, a type of cancer that can affect your sympathetic nervous system
  • leukemia, a type of cancer that can affect your white blood cells
  • rhabdomyosarcoma, a type of cancer that can develop in your soft tissues
  • lymphoma, most often non-Hodgkin’s lymphoma
  • orbital cellulitis, an infection that can affect the tissues around your eye
  • hemangioma, an abnormal collection of blood vessels
  • bleeding behind your eye caused by injury
  • metastatic tumors from a cancer elsewhere in the body
  • connective tissue diseases, such as sarcoidosis

If you develop eye bulging in one or both eyes, make an appointment with your doctor as soon as possible. Be prepared to share your complete medical history with them, including a list of any prescription or over-the-counter medications and supplements that you take.

They’ll also want to know the specifics of your symptoms, such as:

  • When did you first notice that your eyes were bulging?
  • Have they gotten worse since that time?
  • Do you have any other symptoms, especially headaches or visual changes?

After conducting a physical exam, your doctor may order one or more tests. For example, these may include:

Your recommended treatment plan will depend on the underlying cause of your bulging eyes. For example, depending on your diagnosis, your doctor may prescribe one or more of the following:

If you’re diagnosed with Graves’ disease or another thyroid condition, your doctor may recommend:

  • medications, such as beta-blockers or antithyroid medications
  • radioactive iodine or surgery to destroy or remove your thyroid gland
  • replacement thyroid hormone if your thyroid gland has been destroyed or removed

If you have eye problems associated with hyperthyroidism, smoking can make them worse. Quitting may help to reduce your symptoms. Your doctor may recommend a combination of prescription drugs, nicotine replacement therapy, or counseling to help you quit smoking.

Bulging eyes may leave you feeling self-consciousness. Emotional support is important to your well-being. Depending on the cause, you may be able to correct the problem with treatment.