Asked about the most serious risks their clients might face in retirement, financial advisors in the United States say they are most concerned that their clients will be unable to pay for health care costs beyond what is covered by Medicare and supplemental insurance.

Industry research group LIMRA also surveyed retirees about what they saw as serious risks, and for them health care costs came in fourth on a list of five choices. Their top concern was the possibility that Social Security or Medicare benefits might be cut back.

"Healthcare expenditures increase with a person’s age. The most current U.S. Bureau of Labor statistics show that in 2009 retirees age 65 and older paid an average of nearly $5,000 for healthcare," notes LIMRA. "Even with policies designed to 'bend the curve' of cost increases, healthcare expenses are expected to rise an average of 5% each year."

LIMRA also points to a study conducted by Fidelity Benefits Consulting last year, which found that a 65-year old couple in the United States in 2014 could expect to pay an average of $220,000 to cover medical expenses throughout their retirement.

"Overly optimistic health expectations can cause people to underestimate how much they really need. Having enough money to last a through their lives is the top retirement goal for 71 percent of retirees and pre-retirees," concludes LIMRA. "To meet that goal, an effective retirement plan must include a realistic estimate of healthcare costs."