Financial planners also say inheritors must resist entreaties from friends and relatives seeking loans or gifts. Tyrone Phillippi , a certified financial planner in Dayton, Ohio, said one client, against his advice, gave money to a relative to open a bar. “It did not go well — the money was basically gone,” he said.

Teri Alexander , a certified financial planner in Grandview Heights, Ohio, and Dr. Root’s adviser, suggests that clients write a letter to family members and others explaining that they “need time and space” — perhaps several years — before they spend any of the money. “That may keep them at bay — even spouses,” she said.

To Spend or to Save?

About half of all inheritances are less than $50,000, and an additional 30 percent range from $50,000 to $249,000, according to the Federal Reserve. Even small inheritances offer an opportunity to ease some burdens — and to fulfill some dreams — if deployed sensibly, experts say.

Heirs “get into the bucket list immediately, when they should be thinking about how the money can shape the future, whether it’s going back to school to learn a new career or saving a bit more for retirement,” Mr. Phillippi said.

Take the example of two sisters who each received $200,000 when their father died in 2014. One sister, Joy, a retired teacher in her 60s who asked that only her middle name be used to discuss a family matter , said she was investing the money to pay for future long-term-care costs and to leave to her daughter. Joy, who is divorced, said she was living on her pension and savings.

Joy’s sister, a widow, spent the entire gift on a new car and a condo with a large monthly fee that she can no longer afford. “My sister tells me she is struggling and is scared,” she said.

Though there are no rules of thumb for the best uses of sudden wealth, experts say new heirs should set aside cash — enough to cover six months of expenses — in an emergency fund. Retirees, for example, could use this stash to avoid tapping investments in a market downturn.