by Annette Pinder 

Recently, a friend told me that she experienced an episode of Transient Global Amnesia (TGA) while shoveling snow in her driveway on a very cold day. She couldn’t remember anything that happened during that time, and still has no memory of the event. She was given stress and physical exertion as an explanation for why this happened to her.

TGA is a rare, puzzling neurological condition characterized by the sudden onset of short-term memory loss. People with TGA suddenly become unable to form new memories and often can’t recall events from hours or days before the episode. Despite its alarming appearance, TGA is considered benign and temporary, with most people making a full recovery within a few hours. 

During an episode, a person remains awake, alert, and capable of performing complex tasks such as driving, speaking, or following instructions. They typically recognize familiar people and know who they are, but keep asking the same questions—like “Where am I?” or “What day is it?”—because they cannot remember new information. Episodes usually last between one and eight hours and almost always resolve within 24 hours. 

The exact cause of TGA isn’t completely understood, but research suggests the hippocampus, a brain area essential for memory, is involved. Imaging studies sometimes show temporary changes in this region after an episode. TGA has been associated with sudden physical or emotional stressors, such as intense exertion, quick immersion in cold or hot water, strong emotional events, sexual activity, or sudden anxiety. A history of migraines appears more common among those who experience TGA, indicating a possible vascular or neurological vulnerability. 

Importantly, TGA is not caused by stroke, epilepsy, head injury, or dementia. Unlike a stroke, there is no lasting neurological damage. Unlike epilepsy, there is no loss of consciousness or abnormal movements. And unlike dementia, memory function returns to normal once the episode ends. However, because sudden memory loss can also indicate serious conditions such as stroke or seizure, immediate medical evaluation is crucial the first time symptoms appear. 

Diagnosis of TGA is mainly clinical, based on the symptom pattern and their resolution. Doctors might order brain imaging like MRI, blood tests, or an electroencephalogram (EEG) to rule out other causes. There is no specific treatment for TGA itself; care mainly involves observation, reassurance, and ruling out serious conditions. 

The outlook for TGA is very good. Most individuals have only one episode in their lifetime, and having more is rare. There is no proof that TGA raises the risk of stroke, cognitive decline, or long-term memory issues. People can safely return to their normal activities once they have fully recovered. 

Although frightening for both the individual and their loved ones, Transient Global Amnesia is a temporary disruption of memory—not a loss of identity, intelligence, or brain health. Understanding this condition can help lessen fear and anxiety if it occurs. Anyone experiencing sudden memory loss should seek immediate medical care, but for those diagnosed with TGA, reassurance is crucial: The condition may seem dramatic, but it is temporary—and recovery is typically expected.