Also known as: Early-onset Alzheimer's
Meredith receives genetic testing results showing she tested positive for multiple genetic markers for Alzheimer's disease. This drives major plot points including updating her will, choosing guardians for her children, and discussions with Derek about end-of-life care.
Also known as: Prosopagnosia
Rachel Dawson, the mother from a car crash, wakes up after surgery but initially cannot recognize her own son Ethan due to a neurological condition affecting facial recognition. She eventually recovers and recognizes him.
Also known as: Head laceration
Paul, the firefighter who ran into the explosion to save a child, remains unconscious after his hypothermia treatment is reversed. His prolonged unconsciousness becomes a point of concern and conflict between Derek, Owen, and Russell regarding appropriate supervision and care.
Also known as: Mild traumatic brain injury
Matthew Taylor, April's boyfriend, was kept overnight for observation due to concerns about a concussion. He is cleared to leave when his mother comes to pick him up.
Also known as: Post-op infection
Three separate patients develop serious post-operative infections after surgeries. Joyce Basche (dialysis graft) develops fever and infected surgical site, ultimately dying despite surgery. The infections are initially attributed to intern Leah Murphy working while sick, but investigation reveals Bailey was the common link between all three patients, suggesting she may be the source.
Also known as: Dialysis graft infection
Joyce Basche develops a severe infection at her dialysis graft site two weeks post-surgery, presenting with high fever and red, swollen surgical site. Despite surgery to remove the infected shunt and debride the abscess, she dies from the infection.