Rep. Jesse Jackson Jr. will receive in-patient treatment after an unknown condition that caused him to take a leave of absence last month is believed to be worse than previously expected, according to a statement from his office.

The office has not announced how long the Illinois Democrat will be in treatment and is not disclosing what condition Jackson is suffering from.

“Congressman Jackson’s medical condition is more serious than we thought and initially believed. Recently, we have been made aware that he has grappled with certain physical and emotional ailments privately for a long period of time,” according to the statement released today. “At present, he is undergoing further evaluation and treatment at an in-patient medical facility. According to the preliminary diagnosis from his doctors, Congressman Jackson will need to receive extended in-patient treatment as well as continuing medical treatment thereafter. We ask that you keep Congressman Jackson and his family in your thoughts and prayers during this difficult period.”

Jackson, 47, took a leave of absence June 10, but his office did not announce that he had taken a break from his duties until June 25. A statement at the time said that he was taking the absence due to “exhaustion.”

In March, Jackson routed former Rep. Debbie Halvorson in an Illinois primary pitting the two rivals against one another. But he has seen his share of controversy in recent years. He faces an open-ended House Ethics Committee matter related to incarcerated former Illinois Gov. Rod Blagojevich’s attempts to sell President Barack Obama’s old Senate seat. And he also revealed that he had an extramarital affair.

Correction: 4:50 p.m.

An earlier version of this article mistakenly stated that Rep. Jesse Jackson Jr. had a child from an extramarital affair.