A Fine Layer of Body Hair
Seriously underweight women often sprout a layer of fine hair — lanugo — to keep their bodies warm. Lack of certain vitamins and minerals can also be obvious: Hair gets finer and fingernails become weak from too little biotin; without enough iron, hair can fall out. Niacin deficiency causes pellagra, an eczema-like skin condition; lack of zinc leads to dry, cracked skin. A sallow or gray complexion can result from underconsumption of many different nutrients. Depending on the severity of the starvation, symptoms can show up within weeks.
Anorexia is easy to spot; if a woman is extremely underweight, that's a giveaway. It's harder to tell with bulimics — they're generally average or slightly overweight.
If you suspect a friend is making herself vomit, check for yellow or cracked teeth: Stomach acid erodes the enamel. (It's also hard on the esophagus, but you can't see that.) Bulimics generally use the same two fingers on one hand to gag, and they bite down, so look for marks on the backs of their fingers. Pressure from vomiting can burst small blood vessels in the eyes. But those clear up in days, and teeth can be treated, so if your friend is purging, there may not be a sure way to tell.
Women with eating disorders have low self-esteem and are delusional about their looks. Exercise obsession is a clue, as is never eating out. Anorexics are private eaters, and bulimics avoid public bathrooms. Low levels of potassium, electrolytes, and sodium affect energy, and depression often crops up at the same time — look for poor eye contact, slumped shoulders, and bad hygiene or grooming. One patient wore turtlenecks all summer; another piled on layers so people couldn't see her bony frame.
Lack of Periods
It can be hard to interpret symptoms: Someone who throws up once a year might not be bulimic, but what are her feelings and thoughts about it? If a woman restricts her calories so much that she's lost her period, that's a definite sign of anorexia. If you recognize this behavior in yourself or a friend, you must get help quickly. Anorexia has one of the highest mortality rates of any psychiatric disorder.
Change in Appearance
Know what's normal for your friend, and speak up if her behavior or appearance shifts — old pictures are a good way to gauge changes. Say "I'm concerned about you. What's going on?" If she acknowledges a problem, there are great resources to help. Check the American Psychological Association website (apa.org) for a directory of psychologists searchable by ZIP code, or the American Psychiatric Association's site (psych.org), which has diagnostic tools.