Known Unknowns

"Known Unknowns" is the seventh episode of the sixth season of House and 117th overall. It aired on November 9, 2009. The team tries to diagnosed a teenage girl while House is away at a medical conference with Wilson and Cuddy. At the conference House finds something out about Cuddy.

After a wild night out, a teenage girl named Jordan (Anna Attanasio) is brought to Princeton Plainsboro with severely swollen appendages. The team must work to diagnose Jordan, who is less than honest about what happened the night she fell ill. House suspects she is suffering from rhabdo and the fall caused crushed muscles which released toxins that caused swollen joints. But the CT shows no signs of trauma, so House goes in and gets Jordan to pretend to play the drums. Her hands are very weak. House notes that her chart shows low potassium, and rhabdo elevates potassium levels, meaning her potassium had to be extremely low the previous night. This means she can't have climbed stairs, meaning there was no fall. House says something else is causing her low potassium and rhabdo.

Meanwhile, Cuddy, Wilson and House spend a weekend away from the hospital to attend a medical conference. During an 80s party at the convention, House and Cuddy are dancing and talk about their past at Michigan. They mention how they first met, and the night they slept together. House tells her that the next morning he was going to see her and see where things would go from there, but he got a call from the Dean of his first medical school and found out that he was expelled. After that he didn't seem any point to go see her. She leaves him in a haste and later lets him know through Wilson that now she is a mom and she needs someone reliable. When House in turn offers Cuddy to babysit he finds out that she is dating the private investigator Lucas Douglas (Michael Weston) from season five, who is taking care of Cuddy's daughter in place of the babysitter.

Jordan's friend, Phoebe, tells Cameron and Chase what they did the previous night, stating they followed comic book creator Jeffrey Keener (Marcus Giamatti), including going to a restaurant in the building. The food makes Foreman suspect she could be bulimic, which would account for all her symptoms, so Cameron starts her on nutrition supplements and they do a barium swallow to check for mallory weiss tears. However the barium swallow shows no tears, ruling out bulimia. During this test, she has cardiac tamponade - she bleeds around her heart. The team puts her on antiarrythmics. House notes that since her blood pressure dropped during the barium swallow, it can't be a chronic condition. Foreman notes that this leaves just infections and toxins.