The effects of cerebral hypoxia depend primarily on how long the brain is deprived of oxygen. Short-term diffuse hypoxia often produces no effects at all. For instance, a wrestler who loses consciousness with his opponent's arm around his neck will likely regain full functioning after he regains consciousness. People who experience this sort of short-term oxygen deprivation, though, will still experience symptoms. Those include:

• Loss of sensation in one or more areas of the body;
• Confusion, memory difficulties, or impairments of judgment;
• Loss of consciousness;
• Blurred vision or difficulty focusing the eyes on a single point;
• Feeling nauseated or woozy;
• A headache during or after the period of hypoxia.

When hypoxia lasts less than 60 seconds, it is unlikely to cause lasting damage. At two minutes, the risk of brain damage becomes more likely, while at three to four minutes, it becomes a near-inevitability. The long-term effects of cerebral hypoxia can include:

• Damage to specific areas of the brain. The specific prognosis depends on which areas are damaged. For instance, severe damage to regions of the brain that govern speech and language may lead to aphasia.
• Long-term loss of consciousness in the form of a coma. Some patients also enter a persistent vegetative state. This loss of consciousness may give the brain time to heal, but can also be a permanent state.
• Epilepsy or persistent seizures.
• Damage to motor skills, especially fine motor skills. Sometimes this damage is localized to just one region or one side of the body.
• Death, either immediately after the deprivation or due to the side effects of hypoxia, such as stroke or other cardiovascular episodes.
• Birth defects; hypoxia is a relatively common birth injury, and newborns who suffer prolonged oxygen deprivation may suffer chronic diseases such as cerebral palsy.