At 6'6", Tanya Angus towers over her sister. Incredibly, she can't stop growing. Weighing nearly 500 pounds, Tanya barely squeezes into a standard size mini van.
Her mom Karen helps her out of the pool because her 30-year-old daughter's giant size is causing her bones to crumble.
"She walks and she moves like somebody who's in their 70's or 80's," Karen says.
The heartbreaking shocker is that Tanya was once a leggy, raven-haired girl. Once a competitive young diver, Tanya also loved to dance and horseback ride.
But when she turned 20, she suddenly began to mysteriously grow. "I just couldn't fit my clothes anymore," says Tanya.
INSIDE EDITION's Megan Alexander spoke with Tanya. Her feet, hands, and fingers are huge. But Tanya says when her voice got deeper people got really cruel.
"I had a boyfriend back then...he and his mom asked me 'Are you a man?' " says Tanya. "That's degrading"
Tanya was growing an inch a year. When she came home to Las Vegas after several years of living in Michigan, her mom, a nurse, immediately knew that something was wrong.
"[I was] very scared. Very scared. She goes away, and when she comes home, she's three to four inches taller, she looks more masculine, and you don't know what's wrong," Karen tells INSIDE EDITION.
An MRI revealed a tumor the size of grapefruit in her brain's pituitary gland. The tumor was causing her body to excrete 10 times the normal amount of growth hormones.
She takes massive quantities of drugs daily to control the pain, and uses a special device to help her breath at night.
Tanya shares a house with her sister Suzi, who is overwhelmed by the helplessness of her big sister's condition. "There's nothing any of us can do," she says.
The young girl who once rode horses still loves them, and while her bikini days are a distant memory, Tanya dreams of the day she stops growing.
Tayna has had several surgeries to remove the tumor around her pituitary gland, but it keeps growing back. If you'd like more information on Tanya's condition, which is called acromegaly, please visit
www.pituitary.org.