Symptoms:

Symptoms of mild cerebral hypoxia include:

• Change in attention (inattentiveness)
• Poor judgment
• Uncoordinated movement

Symptoms of severe cerebral hypoxia include:

• Complete unawareness and unresponsiveness (coma)
• No breathing
• No response to light

If only blood pressure and heart function remain, then the brain may actually be completely dead.

Signs and tests:

Cerebral hypoxia can usually be diagnosed based on the person's medical history and a physical exam. Tests are done to determine the cause of the hypoxia, and may include:

• Blood work, including arterial blood gases and blood sugar level
• Echocardiogram
• Electrocardiogram (ECG), a measurement of the heart's electrical activity
• Electroencephalogram (EEG), a test of brain waves that can identify seizures and show how well brain cells work
• Evoked potentials, a test that determines whether certain sensations such as vision and touch reach the brain
• Magnetic resonance imaging (MRI)