It is well known that being lonely pays more for your health than living in an unhappy marriage. For example, for your blood pressure, as shown by a preliminary study published on-line in the Annals of Behavioral Medicine.

"That second finding is a surprise because prior studies have shown that married people tend to be healthier than singles. It would take further study to sort out what the results mean for long-term health," said researcher Julianne Holt-Lunstad, an assistant psychology professor at Brigham Young University.

The investigation was made on 204 married people and 99 single adults.

"Most were white, and it's not clear whether the same results would apply to other ethnic groups," said Holt-Lunstad.

The subjects wore blood pressure recording devices that measured the values of blood pressure at random times over 24 hours. Married subjects also completed questionnaires about their marriage. When data was processed, it appeared that increased marital satisfaction was connected to lower average blood pressure over the 24 hours and during the daytime compared to single people, while low marital satisfaction was connected to increased average blood pressure compared to the same category.

During the daytime, the average value of marriage-stressed spouses was about 5 points higher, achieving values considered not-healthy, the next stop towards hearth issues, forecasting heart attack and stroke.

"Few studies of the risk for high blood pressure have looked at marital quality rather than just marital status," said Karen Matthews, a professor of psychiatry, psychology and epidemiology at the University of Pittsburgh, involved in heart disease and high blood pressure investigations.

A 2007 research found a strong connection between our ability to recover from a major health issue and the spouse's personality. Neurotic or anxious spouses were more likely to inflict depression on their partners 18 months after a surgery. Depression is widely recognized as a risk factor in heart attacks and death. Oppositely, the optimism of one spouse provoked beneficial effects for the partner.

Partner's personality cannot be changed, but researches show a person's degree of satisfaction with their marriage is a key influence in their health.