The National Institutes of Health has estimated erectile dysfunction (ED) affects as many as 30 million men in the United States (18 million men over the age of 20), 75 percent of which do not seek treatment. We get it, guys: you’re embarrassed and don’t feel comfortable addressing the issue with your doctor, let alone your partner. But you need to know treatment is available. And we’re not talking about the little blue pill. Viagra and similar medication won’t cure ED if the underlying cause isn’t treated first.

Chronic diseases, like heart disease and diabetes, as well as an unhealthy lifestyle have long been touted as underlying causes of erectile dysfunction. There are also lesser known, and OK, sometimes weird, causes of erectile dysfunction, too. Here are eight more to watch out for.

You Don’t Get Enough D

Vitamin D, that is. Don’t be gross. According to Dr. Erin D. Michos, an assistant professor of medicine at the John Hopkins Hospital, “a growing number of studies point to vitamin D deficiency as a risk factor for heart attacks, congestive heart failure, peripheral arterial disease (PAD), strokes, and the conditions associated with cardiovascular disease, such as high blood pressure and diabetes.” And since heart disease is a well-reported cause of ED (symptoms restrict blood flow and harden arteries), it makes sense some studies have linked D deficiency to the disorder, too.

Apart from soaking up a safe amount of sun, vitamin D is better sourced from food than supplements. Salmon, fortified milk, fortified cereal, eggs, mushrooms, small servings of pork and beef, as well as ricotta cheese are the way to go.

You Work In Health Care

In a survey for, an online clinical directory of dysfunction-focused medical services, men who work in an environment prone to depression and anxiety, like food service staff, health care workers, firefighters, and police officers, were more likely to cope by smoking, drinking, and taking antidepressants — each a risk for ED.

“Anxiety and depression are the leading psychological causes for dysfunction,” Dr. Justin Sitron, a professor in the Center for Human Sexuality Studies at Widener University in Chester, PA, told Prevention. "Erections require the nervous system to trigger them, and if the system is depressed or distracted, then it won't happen."

You Watch Too Much Porn

In a 2013 survey from adult site PornHub, millions of men were watching porn per hour. And according to The Kinsey Institute, 9 percent of surveyed men were unable to stop. Excessive pornography is associated with lower self-esteem, poorer relationship quality, and lower sexual satisfaction.

The American Psychological Association even cited a study from Brigham Young University and the University of Missouri that found men's use of porn was associated with lower sexual quality for both men and their partners. Sexual health professionals are available to help men and their partners address a potential porn addiction, as well as the healthy steps to restore relationship quality.

You Don’t Floss

Israeli researchers found that more than 15% of men with ED also suffer from periodontitis — a severe form of gum disease. “One of the popular theories is that [gum disease is a] chronic inflammatory condition of the whole body so when there are these inflammatory markers possibly caused by gum disease you can get these other signs of inflammation,” Dr. Michael Eisenberg, the Director of Male Reproductive Medicine and Surgery at Stanford Hospital & Clinics, previously told Medical Daily. “Atherosclerosis, a vascular disease, is another manifestation of this sort of inflammatory response so it may kind of predispose us to develop these inflammatory problems in our blood vessels just as they would occur in our mouth.”

You Feel The Need For (Bike) Speed

The hard, narrow seat of a bike can desensitize and damage the nerves and blood vessels in your pelvic floor. Men who frequently go bicycling, spinning, and even horseback riding are at an increased risk for this kind of damage. The damaged blood vessels are what contribute to ED.

Since this is less likely to happen, men who suspect their disorder is tied to their bike should scale back on the amount of miles they log per week. If symptoms persist after that, men should consult with their doctor.

You Snore Way Too Much

The American Sleep Apnea Association reported “untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, impotence, and headaches.” Similarly, a study published in the Journal of Clinical Sleep Medicine found of the 18 million Americans affected by sleep apnea, 63 percent experience relationship problems (including but not limited to ED), 69 percent experience reduced sexual desire, and 46 percent experience reduced arousal. Did we mention sleep apnea affects more men than women?

The good news: sleep apnea, thus ED, can be treated. To find a doctor in your area, click here.

Your Partner Doesn’t Have A Slim Waist

This one makes us roll our eyes, but alas, it’s scientifically sound. A study published in the journal Archives of Sexual Behavior found the slimmer a woman's waist, the more satisfied her partner is and the less likely he is to suffer impotence in the bedroom.

You Have A Big Neck

A waist for a neck? Turkish researchers concluded men with larger necks are at an increased risk of developing erectile dysfunction. “It is a very interesting study,” Dr. David Goldmeier from St. Mary’s Hospital in Paddington told The Sun. “Larger neck circumference is also associated with sleep apnea, which is itself associated with low desire.”

The bottom line: The cause for your ED may not be what you think. Suck it up and schedule an appointment with your doctor. Sorry (not sorry) for the tough love, but if nothing else, know that ED is often believed to be a warning sign of other serious health conditions. Don’t let embarrassment keep you from an overall satisfying life.