At one point or another you’ve fallen asleep in a less-than-comfortable position and suffered the consequences the next day: the aches, the pains, the fatigue. Those symptoms, however, are just the short-term results of one bad night. What you might not know is that your sleeping position — even in the most comfortable of settings — could have lasting health implications that affect your health. What is the healthiest sleeping position? It mostly depends on what’s right for you.

You probably belong to one of three categories: back sleeper, side sleeper or stomach sleeper. Those distinctions might not seem that important, but there’s an entire subset of the medical community devoted to analyzing those specific positions and determining which is healthiest. Jonathan Sherrill, a registered polysomnographic technologist and general manager of the Los Angeles-based Advanced Sleep Medicine Services Inc., is a member of that community.

According to Sherrill, a person’s primary concern when settling into a sleeping position should be comfort.

“Overall, we recommend the position that is most comfortable,” Sherrill says. “The body will naturally acclimate and adjust to whatever position it functions best in.”

However, the sleeping position a person finds most comfortable isn’t always the healthiest.

“In order to sleep and recover, your body has to enter a zone where it’s unaware,” Sherrill says. “It needs to shut off from the external cues of the environment and it needs to go into that recover mode. So while it’s in that zone, it’s not really conscious of what it’s doing. The body could be malfunctioning in several ways.”

Those malfunctions are related primarily to breathing. Chronic obstructions in a person’s air intake can lead to sleep apnea, a disorder characterized by excessively low blood oxygen levels, which over time can result in stroke, heart failure and sexual dysfunction among other negative health effects.

The Back Sleeper

Of the three basic sleeping positions, the back sleeper is the one most commonly associated with sleep apnea.

“For posture reasons we do like people to sleep on their backs, but we also see that people tend to malfunction more in that position,” Sherrill says. “Gravity allows your tongue to relax and during a certain phase of REM sleep your body goes through muscle atonia when your body relaxes so much that you essentially become paralyzed. So when you’re sleeping on your back and your tongue falls back and your muscles are paralyzed, it leads to a higher incidence of sleep apnea in that position.”

The Stomach Sleeper

Sleeping on one’s stomach also can prove detrimental.

“We usually like to rule out the stomach,” Sherrill says. “It’s a position that many obese people will go into naturally. However, in that position you often end up with more backaches. Your stomach is pressing back and your spine enters an awkward posture, which can lead to pain.”

The Side Sleeper

That leaves the side position, which, according to a 2003 study conducted by the London Sleep Assessment Service, is the most popular position among the general population. Over 50 percent of people favor some variation of the side sleeper position during sleep. According to Sherrill and his colleagues, the majority has it right: Sleeping on your side, and specifically on your right side, is perhaps the healthiest position a person can adopt.

“Right is preferred over left,” Sherrill says. “The left position can increase your blood pressure, increase your heart rate and we recommend that people who suffer heart attacks should not sleep on their left side.”

That conclusion was partially echoed in a recent New York Times article exploring the various health effects of right-side versus left-side sleeping. When asked which side was generally healthier to sleep on, Times health expert Claiborne Ray pointed to a 2003 study that found that some people did indeed benefit from sleeping on the right side of their bodies, but that they tended to be individuals with pre-existing heart conditions.

Ray said, “The findings were in keeping with the concept that a left-hand position ‘may exert deleterious effects’ on heart pressure, cardiac output or the functioning of cardiac nerves and thus ‘may be a protective strategy.’”

In other words, there’s research that suggests sleeping on your right side can help prevent circulatory problems and there’s research that indicates sleeping on your right side helps mitigate the effects of pre-existing circulatory conditions. It’s a chicken-egg situation, but in any case the evidence points to a common conclusion: Sleep on your right side, especially if you’ve got a bum ticker.