BEFORE her drinking spiraled out of control, Sylvia Dobrow “drank like a lady,” as she put it, matching her wine to her sandwiches: “Tuna and chardonnay, roast beef and rosé.” But soon she was “drinking around the clock,” downing glasses of vodka and skim milk.

“When you try to hide your drinking from your grandchildren, you do whatever you can,” said Ms. Dobrow, 81, a mother, grandmother and great-grandmother living in Stockton, Calif.

A former hospital educator, Ms. Dobrow’s alcohol consumption became unmanageable after she lost her job and subsequently “lost my identity,” she said.

One night in early 2007, after a particularly excessive alcohol binge, Ms. Dobrow fell out of bed and suffered a black eye. That was when her two daughters, one of whom was a nurse, took her to Hemet Valley, a recovery facility in Hemet Valley, Calif., that caters to adults age 55 and older. Ms. Dobrow, who was 73 at the time, stayed for 30 days, which cost roughly $20,000, about $13,000 of which was covered by insurance. When she returned home, she continued with a 12-step program. She has been sober ever since.

An estimated 2.8 million older adults in the United States meet the criteria for alcohol abuse, and this number is expected to reach 5.7 million by 2020, according to a study in the journal “Addiction.” In 2008, 231,200 people over 50 sought treatment for substance abuse, up from 102,700 in 1992, according to the Substance Abuse and Mental Health Services Administration, a federal agency.

While alcohol is typically the substance of choice, a 2013 report found that the rate of illicit drug use among adults 50 to 64 increased from 2.7 percent in 2002 to 6.0 percent in 2013.

“As we get older, it takes longer for our bodies to metabolize alcohol and drugs,” said D. John Dyben, the director of older adult treatment services for the Hanley Center in West Palm Beach, Fla. “Someone might say, ‘I could have two or three glasses of wine and I was fine, and now that I’m in my late 60s, it’s becoming a problem.’ That’s because the body can’t handle it.”

Many, although certainly not all, of these older individuals with alcohol problems are retired.

Over the course of 10 years, Peter A. Bamberger and Samuel B. Bacharach, co-authors of “Retirement and the Hidden Epidemic,” conducted a study funded by the National Institutes of Health on substance abuse in older adults. They found that the impact of retirement on substance abuse was “anything but clear cut, with the conditions leading to retirement, and the economic and social nature of the retirement itself, having a far greater impact on substance use than simple retirement itself,” said Mr. Bamberger, who is also research director of the Smithers Institute at Cornell University.

But events that arise in later life often require coping skills older adults may not possess. Some retirees are lonely and depressed, and turn to alcohol or drugs to quell their anxieties. Others may drink to deal with late-life losses of spouses, friends, careers and purpose.

“In retirement there can be depression, divorce, death of a spouse, moving from a big residence into a small residence,” said Steven Wollman, a substance abuse counselor in New York, . “For anyone who’s an addict, boredom’s the No. 1 trigger.”

Sandra D., 58, who works in the financial services industry in Toronto, said that her father’s drinking increased so much after he retired that she often took the car keys away from him.

“He and his friends meet for cocktails at about 3 or 4 and then he passes out, which he calls a ‘nap,’ ” said Ms. D., who asked that her full last name not be used. “My dad didn’t plan out his retirement well. My mom was very ill for many years before she passed away, and my dad was a caregiver. He was pretty well looking after the house and taking care of her. When she passed away, there was a very big void for him.”

Ms. D. said her father, an 82-year-old former maintenance worker, doesn’t believe he drinks too much, a common perception among many seniors.

“People are really good at redefining things,” said Stephan Arndt, a professor of psychiatry at the University of Iowa and director of the Iowa Consortium for Substance Abuse Research and Evaluation. “They say, ‘I don’t have a problem, I just like to drink.’ Or, ‘I’m a big guy, I can handle it.’ In the case of prescription drugs, it’s, ‘Well, I got it from my doctor, and it’s for my pain. It’s medication.’ Consequently, they don’t seek help.”

Physicians often aren’t trained to talk to their older patients about chemical dependency — or, perhaps more pointedly in an era of managed care, they often don’t have the time to thoroughly screen a patient. Also, many signs of chemical dependence like memory loss and disorientation resemble normal symptoms of aging. “Is this person confused because they’re messing up their meds, or is it dementia?” said Brenda J. Iliff, the executive director of Hazelden, a residential treatment center in Naples, Fla., that offers special programming baby boomers and older adults for about $21,000 a month. “Is their diabetes out of control, or did they fall and break their hip because they were woozy from Atavan?”

Another misconception is that older adults don’t benefit from treatment. “There’s this lore, this belief, that as people get older they become less treatable,” said Paul Sacco, an assistant professor of social work at the University of Maryland in Baltimore, who researches aging and addiction. “But there’s a large body of literature saying that the outcomes are as good with older adults. They’re not hopeless. This may be just the time to get them treatment.”

Pamela Noffze was 58 when she arrived at Hazelden‘s center in Naples for treatment. At her worst, she was drinking a case of light beer a day, but she didn’t think she had an issue until her daughter threatened to ban her from seeing her grandsons again unless she sought help. “That’s when I knew I had to do something,” said Ms. Noffze.

On her first night at Hazelden, she discovered that she was also addicted to Klonopin, an anti-anxiety medication that her psychiatrist had prescribed in 2009 to help her cope with a divorce. Weaning herself off prescription medications was harder than stopping drinking, she said. Still, she has not had a sip of alcohol or any pills since rehab.

Ms. Noffze, now 61, who lives in Naples and is unemployed, regularly attends 12-step meetings. She said she was astonished at the number of people who “have their cocktails every night, and the next thing they know they find themselves addicted because some doctor gave them Ambien to sleep or they were on pain pills for arthritis or whatever,” she said. “You put those two together and you put yourself over the edge.”

As for Ms. Dobrow, she was so emboldened by her recovery that in 2010 she went back to school to get a credential as a substance abuse counselor. She now works part time counseling older adults at Hemet Valley.

“Losing your purpose in life is the singular thing that hurts people,” said Ms. Dobrow. “We involve so much of our ego in our career, but these last seven and a half years have been the most fulfilling of my life, because I can help people. What is when people used to wear a sandwich board and walk around in a commercial? I feel that mine says ’Hope’ on the front and on the back.”