Three-year-old Gene, the son of comedian Amy Schumer and her husband Chris Fischer, was brought to the hospital for RSV while Schumer was working on "Saturday Night Live" last week.

Schumer posted a video and a series of photos from her week on the set of the show, where she shared what was going on behind the scenes of her hosting gig.

"This was the hardest week of my life," Schumer wrote on her Instagram post. "I missed Thursday rehearsals when my son was rushed to the ER and admitted for RSV. Shout out to all the parents going through this right now." 

According to the CDC, Respiratory Syncytial Virus Infection (RSV) is "a common respiratory virus that usually causes mild, cold-like symptoms."

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Amy Schumer hosting "Saturday Night Live"

Amy Schumer hosted "Saturday Night Live" on Nov. 5 and shared in an Instagram post about her son's hospitalization for RSV that happened while she was preparing for the show. (Will Heath/NBC via Getty Images)

According to the website, even though most people get better in a week or two, it could be serious for infants and older adults. 

In her post, Schumer thanked the "SNL" team for their support during the week. 

"I got to be with him the whole day at the hospital and the beautiful humans at @nbcsnl couldn't have been more supportive," she shared.

"My son is home and better. The reason this show is so fun to do isn't actually the performance or the show itself. It's getting to spend time with the people there," Schumer continued. 

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Amy Schumer in a "Saturday Night Live" skit

The comedian expressed her appreciation for the "SNL" crew in her post. (Will Heath/NBC via Getty Images)

Schumer has hosted "SNL" multiple times since her hosting debut in 2015. 

The comedian wrapped up her Instagram post by saying thank you to some individuals who make up the "SNL" crew and thanked the doctors and nurses who helped her son. 

"The crew! Donna. Jerry. Jodi. Genna. Tom Wally and on and on. Lorne has assembled the most talented people with the kindest hearts. Thank you everyone there and to the doctors and nurses who helped us," she said at the end of her post. 

Amy Schumer with her husband Chris Fischer

Amy Schumer shares Gene with her husband Chris Fischer. (Frazer Harrison/WireImage)

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Schumer's hosting of "SNL" came between her comedy shows. Her last show on the tour is on Dec. 10 in Los Angeles.