We’ve said it before: an estimated 25 million people in the U.S. suffer from sleep apnea. These are cases that are diagnosed, but a study in 2018 went further, estimating that one billion people suffer from sleep apnea worldwide. Knowing the most common sleep apnea risk factors is crucial for a proper diagnosis and treatment plan – and it could save your life.

1. Obesity

Obesity is arguably the most prevalent risk factor for obstructive sleep apnea. For some, extra weight means fatty deposits around the airway. For others, disrupted sleep means hormonal changes that can change a person’s appetite regulation.

Complicating the fact that carrying extra weight changes the anatomy of the airway, having obstructive sleep apnea can also contribute to weight gain.

2. Family history

A family history of sleep apnea does not mean that there is a direct gene linking this condition across the branches of your family tree. Instead, certain hereditary factors like anatomy may create conditions for sleep apnea to arise (more below).

Researchers have discovered and are beginning to investigate what they refer to as a genetic susceptibility to sleep apnea. This may give better insight into just how (and why) sleep apnea is passed down through generations.

3. Anatomy of the airway

If a person has other sleep apnea risk factors and also has a narrow airway, they are at an increased risk of developing sleep-disordered breathing.

4. Structure of the lower jaw

Another anatomical feature that can predispose a person to sleep apnea is a smaller lower jaw. A narrow lower jaw means that the airway is also smaller and narrower.

It can be tempting to think that children, with their tiny jaws and small airways, are at increased risk, but it’s important to consider proportion. When considering the size of someone’s lower jaw or airway, think about its size in relation to the rest of their body. Children can have sleep apnea, but it is much less common than in adults.

5. Large neck circumference

Study after study confirms that adults with larger-than-average neck circumference are at an increased risk of sleep apnea. This may be a function of excessive fatty deposits in the neck that are unrelated to obesity.

For women, a neck circumference larger than 16” contributes to an elevated risk, while a neck larger than 17” is the measure for men.

6. Large tonsils

The final anatomical contribution to sleep apnea is large tonsils. This may be more present in children (along with enlarged adenoids that block nasal passages).

In some case, surgery to remove them completely resolves sleep apnea.

7. Alcohol consumption

There are a variety of sleep apnea causes that are considered preventable, and alcohol consumption is one of them.

Drinking before bed disrupts the hormones that regulate sleep, causing restlessness and a change in brain patterns. A slower arousal response means that the brain is less likely to recognize that the sleeper’s airway is blocked, making what might be minor sleep apnea more severe (and more dangerous).

8. Smoking

Smoking is a sleep apnea risk factor that has a bidirectional relationship with the condition. Research shows that not only are those with obstructive sleep apnea (OSA) are more likely to smoke, but also smokers are predisposed to OSA.

In this case, it doesn’t matter if the chicken or the egg came first.