When you think of an eating disorder, you may imagine anorexia or bulimia — the two most commonly known obsessive compulsive disordered eating conditions. But the less obvious signs of disorder could be an extremely healthy eater, an overeater, or a fitness fanatic. Experts from the National Eating Disorder Association believe approximately 30 million Americans are struggling with a disorder, many of which may not be readily recognized.

"Countless individuals do not meet the clinical criteria to be diagnosed with an eating disorder, but are still struggling nonetheless," Claire Mysko, CEO of the National Eating Disorders Association (NEDA), told US News. "Not all symptoms are immediately apparent, especially if the cases have not had obvious physical effects."

In 2013, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) included a new eating trend called binge eating disorder (BED). This disorder is marked by a person’s inability to control their food intake. In a cyclical pattern, they eat large quantities of food in a short amount of time, which is often followed by intense shame and guilt. BED reportedly affects 3.5 percent of women, 2 percent of men, and 1.6 percent of adolescents.

To add to the number of unknown eating disorder cases, binging, purging, or restricting food intake — inconsistently or on occasion — qualifies as "other specific feeding or eating disorders" (OSFEDS). According to the National Association of Anorexia Nervosa and Associated Disorders, OSFEDS constitute 70 percent of all eating-disorder cases. Because there are often no immediate physical side effects from occasionally exhibiting disordered eating patterns, it’s much more difficult to recognize, let alone diagnose.

Another eating disorder that may be thriving under the radar is anorexia athletica, which is characterized as exercising too much or too intensely for the end result of weight loss. Roughly half of those with any kind of eating disorder might also suffer from this compounding condition.

"Eating disorders can be serious and life-threatening without extreme weight loss or weight gain," Mysko said, "and there can be hidden medical consequences that may be difficult to identify without specific laboratory tests."

National Eating Disorders Awareness Week, which started Feb. 21 and will end Feb. 27, serves as a time to spread awareness and educate the public about the many faces an eating disorder can wear. According to Mysko, this year's theme is early intervention. Getting screened can take as little as three minutes, thanks to an online screening tool provided by the NEDA. It doesn’t officially diagnose eating disorders, but it allows a person to identify certain red-flagged patterns, signs, and symptoms that can help treat unhealthy eating behaviors sooner than later.