If you are below a BMI of 17.5 you fit the criteria for anorexia nervosa, if you purge (and that includes using vomiting, laxative and/or exercize and anything else going) to reduce the impact or get rid of the food you have eaten, you are being bulimic.

There are specific and certain criteria for how long or how many times per week you do this or how severe things are as to weather or not you are diagnosed with either and the difference in something which is even more severe can be labelled further for many. If you are worried you really need to speak to a specialist to be diagnosed. Diagnosis are pretty pointless by themselves, they are mostly there to help buy you treatment from whomever financially covers you for medical care. It really is also very much (as much as they like to disagree) a personal thing; one Psychiatrist can diagnose one thing, another can pull up a different set of DM5 codes...what really matters is that the treatment helps rather than creating a box to put you in.

I have AN and BN, I have had either for nearly 20 years now, it's horrible and not a way to live to put it mildly! I have had periods where my weight has been higher and I have not been bulimic (years at a time) but despite this my eating was very bizarre, controlled, exclusive and avoided many food groups and types. I just ate a lot of a very few things to maintain a healthy weight. It was just as miserable as anorexia nervosa only slightly worse as people assumed I was OK because my weight looked healthy and my bloods were fine. I would say having spoken with professionals they were fully aware I was still unwell but just exhibited different symptoms. Just because you do not fill the criteria for a box does not mean you still cannot be unwell or struggling. Please make sure you ask for help if you are struggling.

There used to be a diagnosis called EDNOS (Eating Disorder Not Otherwise Specified) but this got taken out of the current DM5, it does not mean the disorder does not exist, it just means it has gotten taken out of the book and those with the diagnosis will have new diagnosis. It would be something for a professional to worry about not you; but the fact it used to exist and now has not got the same title does not mean everyone with that diagnosis is fine, it just means they have a new title.