A migraine aura is a warning sign of an oncoming migraine headache. An aura develops gradually. It often begins within 30 minutes before a migraine headache starts. But it can also occur during the headache for some people. It causes short-term symptoms like visual disturbances and physical sensations.

Not everyone who suffers from migraines develops an aura. For those who do, common symptoms of a migraine aura include:

• Visual changes. For example:
  • Zigzag or wavy lines
  • Flashes or sparks of bright or coloured lights
  • Slowly spreading spots
  • Distortions in the shape or size of objects
  • Blind or dark spots in the field of vision
• Numbness or a "pins-and-needles" sensation in one hand or the other.

Other, less common symptoms of a migraine aura can occur, including:

• Tingling or numbness around the mouth and nose or in the arms or shoulders.
• Temporary weakness on one side of the body.
• Brief inability to put words in the proper order, or difficulty finding the right words.