Phillips was reportedly rushed to the hospital on Thursday after suffering a blood infection.
Danny Masterson is "optimistic" that his wife, actress Bijou Phillips, will receive a kidney transplant soon.
In a statement to ET on Friday, the 40-year-old actor's rep revealed that Phillips has been "quietly dealing with kidney disease" for years.
"Bijou was born with small kidneys and has been quietly dealing with kidney disease for the last five years, including being on the transplant list," read the statement. "In an effort to heal her body she has led a stress-free life with a vegan diet, which eventually wasn't enough, and she's been privately having dialysis."
"She recently found out one of her friends is a match and is optimistic that she will have a transplant soon," the statement concluded.
TMZ reported on Thursday that Phillips had been hospitalized in Santa Barbara and was in need of a kidney transplant after suffering a blood infection.
Phillips, 36, and Masterson married in 2011, and welcomed a baby girl named Fianna Francis Masterson in 2014. Fianna just turned 3 years old on Tuesday.