A friend of Margaret Lewis, the missing Durham woman whose body was found in Parkwood Lake last week, said she killed herself to escape the symptoms of a chronic illness.

"This was an illness that didn't have an easy diagnosis," said Fred Gould, a professor of entomology at N.C. State University who described himself as Lewis' good friend and caretaker. "She tried to help herself a long period of time. In the end, all the options were up."

Lewis, 58, made trips to dozens of doctors. "This was somebody who loved life," Gould said. "She didn't kill herself because she was anxious or tired of life."

Police told Gould that Lewis' death was a suicide, he said. Officially all police said Tuesday was that they saw no evidence of foul play.

Gould said at one point Lewis was diagnosed with metabolic syndrome, a group of factors that can lead to heart disease, stroke and diabetes, and then with a digestive disorder. It caused extreme weakness and nausea that kept Lewis from eating regularly. In recent months the already thin and petite woman, lost a lot of weight, he said.

Gould said Lewis, who had a large circle of friends and was a member of Kehillah Synagogue in Chapel Hill, didn't tell him or others that she planned to kill herself.

"This was just my supposition after the fact, that she just decided there were no other options. She couldn't go on," he said. "I just saw the pain she was suffering."

Gould met Lewis through the Triangle Swing Dance Society about two years ago. She was a great dancer who, when she was feeling well, had more energy than most 30-year-olds, he said. A talented individual and a community organizer, she worked at Duke University, until recently, and campaigned for President Barack Obama, he said.

Lewis was reported missing Dec. 9. Her car was found three days later at Parkwood Lake in southern Durham.

During the past nine years, Lewis had experienced heart-wrenching losses.

In January 2003, Lewis lost close friend Janine Sutphen, a cellist with the Durham Symphony. Sutphen was strangled to death and her body dumped in Falls Lake. Sutphen's husband, Robert Petrick, was convicted of her murder and is serving a life sentence without parole. Lewis was a key witness at the trial.

In 2005, Lewis lost her husband Mark Silver, a social worker.

"They were very, very wonderfully in love and very close," said former Northgate Park neighbor Patsy McConnell. "I think her husband's death took its toll."

Lewis sold her longtime home on Butler Street in the Northgate neighborhood in June and moved to an apartment on Revere Road, less than a mile from the lake were her body was found, said Nancy Rizzo, her real estate agent.

Lewis' former neighbors said she told them she was moving to downsize and to be closer to Gould.

McConnell and former neighbors Rebekah Radisch and Deborah Iden described Lewis as sweet and intelligent, but complex and frail.

"I always felt her intentions were kind and her heart good," McConnell said.

A funeral service was held Wednesday at Howerton & Bryan Funeral Home, 1005 W. Main St. in Durham. A shiva service was held that night at Kehillah Synagogue at 1200 Mason Farm Road in Chapel Hill.