Living alone can mean more freedom to do what you want, when you want, but solo dwellers also are more prone to unhealthy habits that increase their risk of serious illness or mortality compared to those who live with others.
Living alone doubled the chance of contracting or dying of severe heart disease for women older than 60 and men older than 50, according to a 2006 Danish study that analyzed population data on more than 138,000 adults.
Seniors living alone are more prone to falls, arthritis and rheumatism, and vision disorders such as glaucoma or cataracts, according to a 2007 study of patients at four group practices in suburban London.
However, single occupants can reduce many of their increased health risks if they are willing to take some simple preventive steps, experts said.
Practice healthy behaviors
The number of Americans living alone has skyrocketed in recent decades: more than 31 million, or 27 percent of all households in 2010, according to the U.S. Census Bureau, up from just 9 percent in 1950.
Not every solo dweller has unhealthy habits. Still, people living alone have increased cardiovascular risk not because they lack someone to watch over them per se, but because they have a greater propensity for smoking and unhealthy eating habits that lead to obesity and high cholesterol levels, the Danish researchers concluded.
These behaviors, as well as excessive alcohol consumption and reduced physical activity, are also key risk factors for cancer and stroke, which, along with heart disease, are the nation's top three killers, said Lori Mosca, director of preventive cardiology at New York-Presbyterian Hospital.
If you live alone and recognize any of these habits as your own, or you have symptoms of heart disease or other health concerns, you should schedule a doctor's appointment and have regular checkups, she said. In the Danish study, single inhabitants with heart disease were more likely to be socially isolated and not see a doctor regularly.
Men age 45 to 74 living alone should take particular care of themselves, Mosca said. In that age group, male single inhabitants are more likely to die from a heart attack than their female counterparts, even when women share similar unhealthy habits such as heavy smoking, a 2007 German study found.
One likely reason for that increased morbidity is that women are often caregivers to men, for example, cooking for them and ensuring they take medications, Mosca said.
Still, even a widower who only knows how to boil a hot dog can lead a more heart-healthy lifestyle if he's willing to change habits, she said.
"He might retrain himself on how to cook healthier in batches and freeze (meals), so he's not tempted to eat out or fix quick things," Mosca said.
Use mobile healthy technology
Receiving effective CPR from another person immediately following sudden cardiac arrest can double or triple your chance of survival, according to the American Heart Association. But simply having another person around may not make a difference when it comes to surviving a serious heart attack, said Eric Topol, a cardiologist at Scripps Health in San Diego.
"When people have cardiac arrest, it's typically in the night during sleep, and the person's spouse is also sleeping," he said. "By the time (he or she) wakes up, the patient may have been dead for a while, but if you have a warning sign and can alert another person in your house, that can be lifesaving."
Anyone living alone with heart disease or another serious chronic disease such as diabetes should wear a medical alert pendant or bracelet to call emergency services if you cannot reach a telephone, Mosca said.
Right now, monitoring technology can allow people with chronic diseases, such as heart disease, diabetes and high blood pressure, to take more control of their disease management, but there's nothing available that automatically dials 911 at an adverse reading, said Topol, also chief innovation officer of the West Wireless Health Institute, a nonprofit group that researches mobile-health technologies.
However, technology that mitigates the "jeopardy" factor of living on your own is not far off, he said.
Protect against falls
Those who live alone, especially seniors, also should take precautions to prevent falls, said Lesley Mills, director and owner of five Connecticut offices of Griswold Special Care, a home health-care agency.
One in three adults age 65 and older falls annually, and of these, up to 30 percent suffer injuries serious enough to limit their mobility or ability to live independently and raise their odds of dying sooner, according to the Centers for Disease Control. But seniors aren't the only ones at risk for home falls, especially in the holiday season, when nearly two-thirds of fall injuries are incurred by people aged 20-49.
Some simple preventive steps include removing tripping hazards such as electric cords and uneven rugs, replacing poor lighting, and installing non-slip mats and grab bars in showers and bathtubs, Mills said.
Holiday season tips for all ages from the CDC include employing safe ladder practices, standing on step-stools instead of furniture, and increasing your awareness of seasonal fall hazards, like decorations on the floor.
Nourish a social network
Finally, solo dwellers with few social contacts may face more serious health impacts. Numerous studies have linked loneliness and lack of social support to high blood pressure, increased mortality for people with heart disease, Alzheimer's disease development, depression and other health problems.
Conversely, interaction with family and friends has been shown to reduce stress, improve blood pressure levels and even increase physical activity, Mosca said.
There are many simple ways to increase your social contacts, especially during the holiday season, Mills said.
"Have as many visitors as possible, set up phone trees, and make reasons to get in touch with people through phone, Internet and webcam," she said.
For seniors, churches and senior centers offer more opportunities to socialize, participate in activities and simply get out of the house, Mills said.