Half of Americans ages 25 to 34 said worrying about finances negatively affects their health, while 53 percent of the same group said money worries have a negative effect on their relationships, according to new survey data exclusively provided to CNBC by E-Trade Financial.
"Our biggest challenges as a generation are financial," said certified financial planner Douglas Boneparth, co-author of the book, "The Millennial Money Fix."
Debt — in particular, student loan debt — has emerged as a major source of stress for under-35 Americans.
"What student debt has effectively been doing is putting off our ability to achieve some of these things we want," said Boneparth, who is also the president of Bone Fide Wealth in New York City. "Buy a house, start a business — we grow up thinking these things are the American dream, and we're having a very hard time getting to them because we see a lot of this money going towards servicing student loan debt."
A rapidly shifting job market and lack of wage growth adds to stress from the high cost of education, Boneparth said.
The Great Recession played a formative role in this generation's relationship to money, financial planners say. The oldest millennials would have been just a few years into their first jobs out of college when it first hit about a decade ago, while the youngest were just entering high school.
"They remember, 'Things were really good, and then dad lost his job and then we had to foreclose on our home,'" said Sophia Bera, a certified financial planner and founder of Austin, Texas-based Gen Y Planning, and a member of the CNBC Financial Advisor Council. "They ask, 'How do I set myself up and my own family so that I don't have the same money worries?'"
Making a financial plan and sticking to it, starting to save early, and thinking long term are the basic pieces of advice financial planners say millennials must follow. That's a must, but maybe not a panacea. The under-35 Americans surveyed by E-Trade are already doing this — the survey of 954 Americans was limited to self-directed investors with at least $10,000 in a brokerage account.
"They haven't had the best job market, they haven't been the best paid," said Mike Loewengart, vice president of investment strategy at E-Trade. "It all combines to create a somewhat unsettling mindset for this age bracket."
The millennial respondents to the survey indicated that branding of wealth in the media hasn't helped — 59 percent of the under-35 investors said images of exaggerated wealth seen on social media and television make them feel less successful. Only 25 percent of investors over age 55-plus agreed with that statement.
The E-Trade survey data supports broader demographic findings that younger Americans are experiencing greater levels of stress. Scientific researchers have found links between stress and a variety of health problems.
Breaking down monthly spending into fixed, variable and discretionary also can help young adults deal with money worries, said Ellen Siegel, a senior financial planner at Plantation, Florida-based Legacy Wealth Management. She goes through an "awareness process" with her younger clients to help them understand their financial commitments and where expenditures can be trimmed.
Credit cards can pose another problem for young spenders, Siegel said. She advises switching to cash and envelopes if it continues to be a serious issue. She tells her clients to put the card in a plastic bag, put that bag into a cup of water and put that in the freezer.
"Freeze your assets," she said. "It's there if you need it for an emergency, but you have to work to get it out."