This article appears in Senior Care Guide 2018.

One in 10: That’s the number of Americans older than 60 who has experienced some form of elder abuse, according to the National Council on Aging. For people with Alzheimer’s or dementia, that number jumps to 50 percent.

While those numbers are shocking, the organization reports that may be just a drop in the bucket because only 1 in 24 cases is investigated by a social worker or law enforcement, and fewer end up being prosecuted.

The main forms of elder abuse include physical and sexual abuse, neglect, financial abuse and institutional abuse, such as neglect in nursing homes, said Maria Duggan, adjust assistant professor at the University of Southern California Suzanne Dworak-Peck School of Social Work.

Physical abuse is the most common, often resulting in recognizable patterns of injury such as to the neck and head, according to a 2015 study published in the New England Journal of of Medicine.

“Most commonly, the perpetrator of elder abuse is an adult child or spouse, usually male. For example, a typical perpetrator would be an adult male child of the victim,” Duggan said.

Financial abuse is also prevalent.

“Over 50 percent of the reported cases of elder financial exploitation, namely illegal seizure of funds or other assets, are carried out by family members or friends rather than strangers,” said Thomas Blomberg, executive director of the Center for Criminology and Public Policy Research at Florida State University.

In a study of elder financial exploitation in the Florida Villages retirement community, the largest such community in the United States, Blomberg found that the majority of “stranger” financial exploitation incidents were related to home services or disputes with contractors.

“A number of individuals described incidents where a deposit was given for home repairs or services, and services were never received,” he said.