context: The cause of Alzheimer's disease is poorly understood.[1] About 70% of the risk is believed to be genetic with many genes usually involved.[4] Other risk factors include a history of head injuries, depression, or hypertension.[1] The disease process is associated with plaques and tangles in the brain.[4] A probable diagnosis is based on the history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes.[5] Initial symptoms are often mistaken for normal ageing.[1] Examination of brain tissue is needed for a definite diagnosis.[4] Mental and physical exercise, and avoiding obesity may decrease the risk of AD; however, evidence to support these recommendations is not strong.[4][12] There are no medications or supplements that have been shown to decrease risk.[13]
question: How is Alzheimer's diagnosed?
answers.text: history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes based on the history of the illness and cognitive testing with medical imaging and blood tests to rule out other possible causes