The destruction of nerve cells (neurons) leads to a decrease in neurotransmitters (substances secreted by a neuron to send a message to another neuron). The correct balance of neurotransmitters is critical to the brain.
By causing both structural and chemical problems in the brain, AD appears to disconnect areas of the brain that normally work together.
About 10 percent of all people over 70 have significant memory problems and about half of those are due to AD. The number of people with AD doubles each decade past age 70. Having a close blood relative who developed AD increases your risk.
Early onset disease can run in families and involves
Late onset AD, the most common form of the disease, develops in people 60 and older and is thought to be less likely to occur in families. Late onset AD may run in some families, but the role of genes is less direct and definitive. These genes may not cause the problem itself, but simply increase the likelihood of formation of plaques and tangles or other AD-related pathologies in the brain.
