Madonna has a sick body. She lured me in with the sensual softness of her "Like a Virgin" phase; inspired me with the provocative androgyny of the "Express Yourself" era; and impressed me with the firm ballet-barre derriere of her "Dance Floor" days. Today her every muscle is defined with such intensity that her veins look like long ropes of licorice. She wears that little red string on her left wrist rain or shine, sweat or video shoot, to represent her connection to the Jewish mystical study of Kabbalah. Yeah, I think she looks a little extreme, but I wouldn't mind being in such fantastic shape that I could tour the world with a two-hour dance fest at the age of fifty. Madonna outswivels Beyoncé, and that's no easy task.

Every body tells a story. Here's my quickie interpretation of Madonna's: The longer she's been around, the more shit she has to take, the tougher her skin gets. Her body has become a missile- defense shield against criticism. At the same time, she's a weapon. She looks like she could crush your head between her thighs while she's prancing around singing "Holiday.” You don't mess with Madonna. To me, she is an example of unrelenting strength.

I also have a sick body. Not fabulous like Madonna's; I mean, literally sick. In 1999, I was diagnosed with a rare, vascular autoimmune disease called Wegener's granulomatosis. At the end of 2003, it flared like Russell Crowe in a hotel lobby. Wegener's caused my immune system to work overtime, fighting an invader that wasn't there. No one is certain how one contracts vascular autoimmune diseases, which include lupus, scleroderma, and hyperthyroiditis, and no one knows how to cure them. Doctors treat serious autoimmune diseases like they do cancer, with a combination of steroids and chemotherapy, hoping to crash and burn the system into a long-lasting remission. There are 50 million Americans living with autoimmune diseases, and more than 75 percent are women. One in nine women of childbearing years develops an autoimmune disorder. To give you some perspective, one in sixty-nine women below the age of fifty is diagnosed with breast cancer.

Cancer is an outside invader your immune system must fight; Wegener's is created by your system itself. If cancer is a playground bully you have to stand up to and fight, autoimmune disease behaves more like the mean girl in the school cafeteria. Mysterious. Nefarious. Insidious. She has no reason to pick on you, but she subtly does her dirty work, tricking your super-well-behaved-up- to-this-point immune system into attacking some innocent cells that were just hanging out with their innocent cell friends. You get sicker and more unsure of yourself and your body. By then, it's too late. You become what's wrong with you. If you don't get better, there's no one to blame but you. Autoimmune disease feels like a bout of low self-esteem that's gone completely off the rails; it's awful hard to love and accept yourself when it's you you're fighting. It's even tougher to trust yourself to make the right treatment decisions. On top of that, for many of us women our bodies have gone through so much diet drama that we no longer know how to listen and respond in a rational way.

If autoimmune means that your body starts working against you, then I say fat is the ultimate autoimmune issue. Being fat and being sick have a lot of similarities. In both cases, my body was doing something I didn't want it to do (gaining weight/screwing up my immune system). I tried everything I could to make it change (lose weight/get healthy). I was willing to go to any lengths, spend any amount of money, listen to anyone who might have the answer. When I failed (to get thin/get better), I felt like it was my fault. I clearly didn't want it badly enough. I didn't love myself enough. If only I had the willpower to triumph over this one problem (fat/sick), the rest of my life would fall into place.

After an insane number of false starts and one particularly dehumanizing experience at the Duke Diet & Fitness Center, I realized I wasn't gonna get skinny. Lack of willpower was not the problem. The body I was born with was the one I had, and if I couldn't love it, at least I could learn to live with it. So I wrote a book, The Fat Girl's Guide to Life, hoping the story of my experience could be therapeutic for other women. My body's story had a happy ending.

Just when I had a completely new and well-deserved outlook about myself, finally some major appreciation for my beauty and my body, Wegener's struck. The power I felt over my appearance, the control I'd worked so hard to earn, completely slipped away due to illness, treatment of that illness, and one seriously messed-up liver. I had the positive image thing locked down, and suddenly I'm inside, looking out of some other body, going, "What the hell happened?” I found it enormously rude that higher powers—let alone my own immune system—had compromised my newly discovered beauty and my recently discovered pride by taking away my health and my looks. So a body battle that I thought I'd won started again, a different fight on the same battlefield. I turned to doctors, then healers, and more than once to Madonna for strength and support. Turns out, the story of my body had a sequel. Here it is.

Excerpted from Are You My Guru?: How Medicine, Meditation & Madonna Saved My Life by Wendy Shanker. Published by NAL Trade. Copyright © 2010 by Wendy Shanker.