More than six million Americans are living with Alzheimer’s disease.By 20-50, that number is expected to more than double.

Now, researchers are working to identify some risk factors for this mysterious disease.

Alzheimer’s disease is both devastating and deadly. In fact, it’s the sixth leading cause of death in the U.S.

One of the biggest problems doctors face is that symptoms typically don’t appear until the disease has progressed.

That’s why researchers are trying to better identify those at risk for Alzheimer’s. A recent study found people who develop infections like herpes simplex virus type one or cytomegalovirus in mid and late life are more likely to suffer from Alzheimer’s and other dementias.

Other research found people who had viral encephalitis, which is essentially inflammation of the brain caused by a virus, were at least 20 times more likely to be diagnosed with Alzheimer’s than those who didn’t have the condition.

Some of the latest research also suggests other possible risk factors include having a head injury, experiencing hearing loss, heart disease, untreated depression, and living in social isolation.

Recognizing these risk factors could help doctors spot the disease earlier – which is key to a better outcome.

Researchers say age is the single most important risk factor when it comes to Alzheimer’s disease. The likelihood of developing it doubles every five years after you reach age 65. However, about one in 20 people have early onset and are younger than 65.