Photo credit: bevocalspeakup.com

Anorexia is not a choice and it's not just a desire to be thin — it's a potentially life threatening disease.

Singer and actress Demi Lovato, who publicly battled anorexia as a pre-teen and teenager, described it best on Twitter.

"There's a wide misconception that anorexia and/or bulimia is a choice and you often hear people say things like 'Why doesn't she just start eating?' Or even 'Just stop throwing up.' It's the ignorance and lack of education on mental illnesses that continues to put mental health care on the back burner to congress even though this is an epidemic that is sweeping our nation, and causing more and more tragedy every day," she wrote.

"Starving is not a 'diet' and throwing up isn't something that only extremely thin men or women do. Eating disorders do not discriminate. Neither does any other mental illness. These are deadly diseases that are taking lives daily."

Someone with anorexia nervosa has a distorted body image and an exaggerated fear of becoming overweight or obese. Experts say the mental disorder is caused by a combination of biological, environmental and psychological factors.

According to Web MD, the risk for anorexia increases if you have a family history of an eating disorder, if you have low self-esteem, if you feel social pressures to be thin, and/or if you have depression or anxiety. Parents should be concerned if their child or teen starts worrying about his/her weight at a young age, becomes strict with a diet and/or intensifies his or her exercise routine.

For Lovato, she said she compulsively overate at a young age. At 12, when she was bullied for being "fat," that's when she stopped eating.

In an interview with Refinery 29 last month, Lovato said, other than the bullying, bipolar disorder also contributed to her anorexia. She was diagnosed with the disorder while in rehab in 2011. She said the diagnosis allowed her to get the help she needed and to figure out a treatment plan to address both her anorexia and bipolar disorders respectively.

For the last three years, she has stopped drinking alcohol and has maintained a meal and exercise plan put together by her trainer.

"I love seeing muscles rather than bone. I'm healthier than I've ever been," she said.

Lovato recently launched the campaign "Be Vocal: Speak Up for Mental Health." Her goal is to encourage people to play an active role in their own mental healthcare and to not be ashamed to talk about their own disorders.

“Asking for help when you are struggling is a sign of strength. Using my voice has always been a part of my professional life, but that wasn’t always the case when it came to bipolar disorder. Despite the setbacks, I finally found the strength to speak up," she said.