Stroke is a medical emergency, and the warning signs usually occur suddenly. Call your doctor immediately if you experience any of the following:

• Sudden and severe headache
• Weakness or numbness on one side of the body
• Loss of vision or having a visual disturbance, especially if it occurs in only one eye
• Dizziness or confusion
• Loss of balance
• Slurred speech or difficulty communicating (including difficulty understanding or having trouble finding the right words)

The appearance of one or more of these symptoms might be a warning sign that a stroke is in progress.

In some cases, strokes are preceded by one or more "mini-strokes," called transient ischemic attacks (TIAs). TIAs are brief episodes of stroke-like symptoms that usually last five to 20 minutes. If you have stroke-like symptoms that disappear without treatment, you still need to see a doctor right away. A TIA shows that you are at risk for a stroke soon, so your doctor needs to evaluate the condition of your heart and arteries and talk to you about how you can reduce your immediate stroke risk.