When it comes to retirement, we've all heard the same advice about saving early and often.

The hard truth, though, is that most Americans aren't saving enough, leaving them unprepared to retire. In fact, the median amount working-age American families have saved for retirement is just $5,000, according to a report by the Economic Policy Institute.

nest egg sitting on pile of money

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Nearly everyone is at risk of running out of money during retirement, according to a study by the Employee Benefit Research Institute -- even those with high incomes. According to the report, 8% of the highest-earning baby boomers are also expected to run out of money during retirement, assuming they retire today and their retirement will last 20 years.

So what can you do to make sure you don't ruin your chances of retiring comfortably? Start by avoiding these common mistakes.

1. Underestimating health-related expenses

Healthcare is expensive, and you're more likely to suffer illnesses and injuries as you age. Health problems such as Alzheimer's and hip fractures from falls are far more common in older adults, and they're also incredibly expensive to treat. (The average cost to care for a person with Alzheimer's during the patient's last five years of life is about $287,000, and the average hospital visit after a fall costs about $30,000.)

Medicare will help cover some of the costs of health problems, but that doesn't mean you won't have to pay anything out of pocket. You'll still be responsible for your deductible, coinsurance, and copays, and Medicare doesn't cover long-term care, eye exams, most dental care, or hearing aids.

What to do:

One option is to consider long-term care insurance. Long-term care can be incredibly expensive -- for example, living in a nursing home can easily cost $50,000 to $100,000 per year . The downside to long-term care insurance is that premiums can cost several thousand dollars per year, and they're even more expensive if you wait until after age 65 to buy a policy.

Another option is to use a health savings account (HSA). If you qualify for an HSA and you're aged 54 or younger, you can contribute up to $3,400 (if you're an individual) or $6,700 (for families) in pretax income in 2017. If you're over age 55, you'll be able to contribute an extra $1,000 per year to catch up. Like a 401(k), HSAs give you an up-front tax break on contributions, and these funds can also be withdrawn for eligible medical expenses on a tax-free and penalty-free basis.

2. Moving too hastily

Many people have dreams of starting a new adventure in retirement by moving to a new home. The problem with this, though, is that many people don't consider how much it costs to move, and costs like property taxes and real estate prices may be much higher than they initially expected.

There are also a variety of other factors to consider when moving, such as the cost of living in the area, the healthcare quality (some states, such as Utah, are renowned for their best-in-class doctors and affordable healthcare), and crime rate in your desired neighborhood.

What to do:

Before you make any big decisions, do lots of research. Look at home prices in your desired area, and also check out property, income, and sales taxes, as well as the crime rate. Compare these figures to your current home and neighborhood to see if it's a place you can afford and would like to live. Also don't forget to include moving costs so you're not caught by surprise when it comes time to move.

If you can, take a trip to your potential new town and visit for a week or two. This way you can discover things you otherwise wouldn't have found out before moving in, such as what traffic looks like on a daily basis and whether you feel safe and comfortable in your preferred neighborhood.

3. Relying on Social Security

Social Security benefits are a great perk for retirees once they reach the full retirement age, but don't take them for granted.

According to the Social Security Board of Trustees, the Social Security program will run out of cash reserves by 2034. Because baby boomers are retiring en masse, that leaves fewer workers to replenish the fund through payroll taxes. And while Social Security won't run out of cash completely -- after all, there will always be tax revenue coming out of workers' paychecks -- it's possible that benefits may have to be cut in the future.

This means that the 51% of retirees who say they're relying on the benefits to make up 41% to 100% of their income during retirement may be in for a rude awakening in 20 years.

What to do:

Your best bet is to save as much as you can as early as you can to grow the biggest nest egg possible. Use a retirement calculator to determine how much income you'll need to get by without the help of Social Security, then see how much you'll have to save each month to get to that point by the time you retire.

It's also wise to live below your means during retirement to conserve your money and avoid having to rejoin the workforce in your golden years. Then, if Social Security doesn't experience the expected cash problems, you'll be left with extra money to enjoy -- and if it does, you'll be prepared.

Retirement is supposed to be a time of relaxation and fulfillment, but it can't be difficult and stressful if you're not prepared. If you do your research and plan accordingly, you'll be able to live your retirement life to the fullest -- without worrying about money.