(HealthDay News) -- Traumatic brain injury, most often a concussion, is caused by a sharp and sudden blow to the head. It may be stem from a car accident, football tackle or an unfortunate fall.

If you suspect a TBI, you should seek immediate medical attention, the U.S. Food and Drug Administration says. A doctor may conduct a neurological exam to evaluate thinking, movement, sensory function, coordination and reflexes.

The FDA says typical symptoms of a mild TBI include:

• Headache.
• Confusion.
• Blurred vision.
• Behavior changes.

The agency says these additional symptoms indicate a more serious brain injury:

• Nausea or vomiting.
• Slurred speech.
• Weakness in the arms or legs.
• Problems with thinking.