An aneurysm is a weak spot that balloons out from the walls of a blood vessel. Aneurysms can occur in many places in the body, but brain aneurysms are among the most dangerous. If an aneurysm ruptures in the brain, it leads to a hemorrhagic stroke, which can be life threatening. The National Institutes of Health estimates that up to 5 percent of Americans may have a brain aneurysm that hasn't been detected. Some unruptured aneurysms cause no symptoms, but others give warning signs.
Headache, Often Above and Behind one Eye
An unruptured brain aneurysm can put pressure on brain tissues, causing pain. The optic nerve is particularly susceptible to this, and according to the Mayo Clinic, many brain aneurysms cause headaches in one precise spot, above and behind one eye.
Changes in the Appearance of a Patient's Eyes
Some symptoms of an aneurysm are observable to others. According to the Brain Aneurysm Foundation, a swelling aneurysm putting pressure on the optic nerve can cause a patient's pupils to dilate, and one may appear larger than the other. In some cases, one eyelid may droop.
Changes in Vision
A patient with an unruptured aneurysm may experience blurred or double vision. According to the National Institutes of Health, a small number of patients may temporarily lose their vision due to an aneurysm. Changes in vision may occur in one or both eyes.
Weakness or Paralysis on One Side of the Face
Though more often associated with a ruptured aneurysm, numbness, weakness or paralysis of one side of the face can occur with an unruptured aneurysm.
Neck Pain
Not all brain aneurysms cause symptoms in the eyes. Aneurysms located deeper within the brain, according to the National Institutes of Health, may cause neck pain or stiffness.
