Alzheimer's disease might damage the brain in two distinct phases, a new study suggests. An early phase that occurs slowly and silently appears to lay the groundwork for a second, more widely destructive phase of Alzheimer's,

An analysis of the genetic activity of brain cells in individuals who have died with Alzheimer's disease has revealed the condition progresses in two stages; a slow increase in inflammation, followed by a more rapid degeneration.

Alzheimer’s disease may damage the brain in two phases, according to new research published in Nature Neuroscience on Monday.

Alzheimer’s Disease May Damage the Brain in Two Phases - NIH Study Uncovers Which Cell Types May Be Harmed First

Each year, about 2.5 million people suffer from traumatic brain injuries (TBI), which often increases their risk of developing Alzheimer's disease later in life.

"The results fundamentally alter scientists' understanding of how Alzheimer's harms the brain," researchers say.

New research suggests the disease occurs in two phases, including one in which changes happen gradually – and 'quietly.'