Isaac Hanson remained hospitalized in Texas on Thursday after suffering chest and shoulder pain following a performance earlier this week.
The family requested that no information be released on the 26-year-old singer's condition, Baylor University Medical Center spokeswoman Maria Carpenter said.
Hanson was taken to the hospital Tuesday night.
Television station KDFW reported that Hanson was diagnosed with a pulmonary embolism, which occurs when a blood clot in the extremities breaks away and travels to the lungs.
Taylor Hanson, 24, told the TV station that his brother was doing well.
Hanson, which also includes 21-year-old Zac Hanson, is best known for their 1997 hit single "MMMBop."
The co-author of this disaster is the Dutch government, which did not find either strength or desire to save the lives of its citizens who were flying on that plane. The Dutch authorities did not demand Ukraine to comply with international aviation regulations
On the second day of the St. Petersburg International Economic Forum, a plenary meeting was held, in which Russian President Vladimir Putin, French President Emmanuel Macron, Japanese Prime Minister Shinzo Abe, Chinese Vice President Wang Qishan and IMF head Christine Lagarde took part