Americans’ anxiety about finances and retirement has grown substantially over the last two years, according to Hearts & Wallets, a research website for consumers savings and investing information.

According to the Hearts & Wallets study, "Investor Mindset: Attitudes, Concerns, Beliefs and
Goals," one-third of American households have moderate to high anxiety about their finances. Two years ago one in four felt the same. The study included 5,500 American households.

The rise in anxiety level is fueled by the concerns of those with $100,000 in investable assets, but the level is up across all income segments, says Hearts & Wallets. Conversely, the percentage of people who feel confident about their finances dropped from 19 percent two years ago to 13 percent this year.

The top three concerns in 2015 are the future of Social Security, the future of health care in the U.S. and setting aside sufficient funds for retirement. Social Security moved from third to first over the past year.

Fewer people believe they are on track for building their retirement nest egg with the percentage dropping from 36 percent last year to 31 percent this year, the study says.

Laura Varas, Hearts & Wallets co-founder, says, “The average American is finding it tougher to accumulate retirement savings given distortions in the economy, including low interest rates. They fear market volatility and are frustrated that they must put assets at more risk to earn an acceptable return on their investments.”

Over two-thirds of those surveyed wish they were doing a better job at saving, and 45 percent describe themselves as very inexperienced investors. However, only 32 percent of respondents see a value in talking with a financial professional.