His mother had a mental illness, and his father was often absent, as well as often becoming violent towards Alex and his mother. Alex began wrestling in high school,[5] and eventually physically confronted his father - after this, his father did not return. Alex has a younger brother, Aaron, and a younger sister, Amber; they were all placed in foster care for 5 years. Though Aaron and Amber only had a few foster families, Alex went through 17 foster families in 5 years before he reunited with his siblings. It is revealed in later seasons that Aaron was diagnosed with schizophrenia and tried to kill Amber. Alex was present when Aaron had to be committed to a psychiatric ward.
Alex secured a position in the surgical residency program at Seattle Grace Hospital after graduating from the University of Iowa. He initially makes a poor impression on his fellow interns meeting fellow interns Meredith Grey (Ellen Pompeo), Cristina Yang (Sandra Oh), George O'Malley (T.R. Knight), and Izzie Stevens (Katherine Heigl) whom he later taunts when he discovers she used to be a lingerie model. After initial disagreements, Alex reveals to Izzie that his father was a heroin addict who used to beat his mother. He became a wrestler so he could defend his mother, and attended university on a wrestling scholarship. He and Izzie begin a friendship. At the end of the first season, George contracts syphilis from Alex through nurse Olivia Harper, causing animosity between the two.
Alex asks Izzie out on a date, but he is thrown by the news that he has failed his medical board exams. Izzie is offended since he pays no attention to her during their date and so informs him that she no longer wants to go out with him. He later freezes during an emergency operation, needing George to take over from him. Alex's relationship with Izzie is damaged when he experiences erectile dysfunction with her. He goes on to sleep with Olivia again, and is caught by Izzie and they break up. After retaking his exams, Alex manages a pass, and reunites with Izzie after a bomb scare in the hospital. They break up again, however, when Izzie falls for cardiothoracic patient Denny Duquette.
Alex helps Izzie recover from Denny's death and advances Izzie but Izzie backs away since she is still in the process of getting over her loss and they remain friends. Alex spends a period of time working under neonatal surgeon Dr. Addison Montgomery (Kate Walsh), and though he is later released to work for plastic surgeon Dr. Mark Sloan (Eric Dane), he finds his interest returning to Addison's firm. Addison is attracted to Alex, and the two share a kiss and later sleep together. In the aftermath of a ferry accident, Alex rescues a pregnant woman (Elizabeth Reaser) who awakes with amnesia, and grows close to Alex as he helps her forging an identity for herself, picking out the name Ava. After she gives birth to her daughter, Ava's memory eventually returns, although she tries to hide it from Alex as she had recently left a bad marriage. He convinces her to tell him her true identity, and she reveals herself to be Rebecca Pope. Alex turns her down after realizing she's married, feeling that he is not good enough for her.
Rebecca returns and she and Alex sleep together before she goes back to her husband. Alex has a brief relationship with intern Lexie Grey (Chyler Leigh), but chooses to be with Rebecca when she returns and tells him she is pregnant. After Rebecca attempted suicide, Izzie convinces Alex to admit her for psychiatric help due to Rebecca's hallucinations of her pregnancy. Alex later breaks down in Izzie's arms, and the two kiss.
Later in their relationship, Izzie begins hallucinating about Denny, and uncovers the fact she has metastatic melanoma (Stage IV) with an estimated chance of 5% survival. It is revealed that Izzie's hallucinations of Denny are, in fact, caused by her tumor. Alex is shocked by the news, but finds the strength to stay by her side. Izzie plans a wedding for Meredith and Derek, but when Derek finds Izzie has another inoperable tumor in her brain, they give the wedding to Izzie and Alex, who marry in front of all their friends. Izzie debates whether or not she should undergo a risky surgery to remove her tumor and Alex supports her, but eventually insists that she should have the surgery. Alex performs CPR on Izzie after she flatlines.
Izzie regains a heartbeat but is soon fired leaving Alex a Dear John letter and no clue as to her whereabouts. She later returns to the hospital and says to Alex, thinking he had a hand in getting her fired, that she could not forgive him for talking to the Chief. Alex says he could not forgive her either for not giving him the benefit of the doubt and leaving without talking to him first. Alex re-kindles an old flame with Lexie. Alex seems to have recently found that his calling is actually Peds and not Plastics as he had decided in the earlier seasons. Seeing Alex's ability to handle child patients, Dr. Arizona Robbins shows an interest in mentoring him for that specialization. Alex's brother Aaron comes to Seattle Grace for surgery, and lots of painful memories resurface because of this. Meredith discovers Alex, along with Aaron and their sister Amber, had been in foster care for five years when their mother could not take care of them. Alex is also served with divorce papers from Izzie. Alex is shot in the hospital by a deceased patient's husband, but survives with the help of Lexie and Mark. While undergoing treatment, he mistakes Lexie for Izzie.
Following the shooting, Lexie has a mental breakdown in front of Alex and he walks away. Dr. Bailey bars Alex from surgery until he has the bullet removed, which he later allows her to do. Alex realizes that his passion lies in Pediatric Surgery. He is further shown to be excellent with children, comforting with a young patient while growing her a new trachea. He immediately gets on the wrong side of new Pediatric attending Stark while Arizona is on leave Alex then attempts to sleep with virgin April Kepner after visiting his mom in Iowa when his brother was diagnosed schizophrenia. Alex and Meredith perform an emergent surgery on a young boy by themselves during the night shift, dealing with the angry fallout from Stark (who would not answer his pager) but gaining the wordless approval of the Chief. Alex is thrilled when Arizona returns from Africa and hopes she will come to work for the hospital again. In the meantime, Alex falls for the new OBGYN attending, Lucy Fields, and they start a relationship after she kisses him. Alex finds out about Meredith sabotaging her Alzheimer's clinical trial and rats her out in attempt to get Chief Resident.
The adoption counselor takes away Zola, the child Meredith wanted to adopt. Realizing his mistake, Alex apologizes to Meredith who forgives him shortly after. As the end of the fifth year of residency is near, the surgical residents, including Alex, prepare for their board exams for the different fellowships they plan on joining. Though Alex is late for his exam because he had to treat a patient, he ends up passing. Dr. Webber tells him that Johns Hopkins Hospital, which has the top program in the country, has been very impressed with him and has decided to
create a position in pediatrics surgery for him and accepts the position. After finding out his decision, his current boss, Dr. Arizona Robbins, yells at him and takes his place on a plane that later crashes.
Following the rescue of his colleagues, Robbins' health deteriorates and amputates her leg. He extends his stay at Seattle Grace until a replacement for Robbins is found, but when he learns that the replacement will send the exchange program to UCLA, he decides not to leave. Karev buys Meredith's old house from her, and Cristina becomes his roommate. Karev forms a friendship with new intern, Jo Wilson that eventually develops into romantic feelings towards each other. Alex admits his love for Jo, and the two kiss and become a couple.
Alex's estranged father, Jimmy, who he hasn't seen in 18 years, is admitted to the ER as a patient. After being discharged, Jimmy plays with his band at a bar, and Alex spends several nights watching his father perform onstage. Unknowing that Alex is his son, Jimmy confides in Alex that he had another family that he hasn't seen in years. This made Alex upset and he punched Jimmy at the bar. Once returning home, Alex unleashes his hurt and anger on Jo for having encouraged him to reconnect with his father. His father returns suffering from symptoms of withdrawal and hallucinations of the past where more is revealed about Alex's childhood. Jimmy tells Alex he knows that he is his son and Alex yells at his dad stating that "I WAS THE DAD". His dad later goes into cardiac arrest and is brought into surgery, fate unknown. Alex kisses Jo at April's wedding wanting to start a family with her. That night his dad died, due to a mistake by intern, Shane Ross, and Alex is upset. He punches Ross and is later comforted by Meredith.
Upon the completion of his fellowship in Pediatric Surgery, Alex is given an offer to work at Dr. Oliver Lebackes' private practice office, claiming that he will have more flexible hours and "a big fat paycheck". Alex takes this offer happily. Robbins is initially angered by this decision and thinks that Alex is choosing money over substance. Eventually she realizes that he has become a wonderful surgeon and that she is happy to see him go. He later discovers that he isn't happy working at the private practice and expresses a desire to return full-time to Grey Sloan. When Cristina leaves for Switzerland, she leaves Alex her share of the board, including her seat.
Alex is fired by Dr. Lebackes when Maggie Pierce accidentally reveals to him that Karev was thinking about leaving the job. Webber recommended Bailey to fill Yang's board seat after she left, so Bailey and Alex fight over the chair. They both make presentations to the board and eventually Bailey wins, with a unanimous vote in her favor. He is hired back as an attending Peds surgeon and takes over full-time as Arizona pursues a fellowship with Dr. Herman. Alex continues to date Jo and his friendship with Meredith grows stronger than ever, with him taking on the role of her new person. When Derek dies and Meredith runs away, Alex is upset by her leaving without telling him where she went and calls her everyday. Eventually she calls him, tells him she is okay, and to stop calling. When she goes into labor and gives birth to Ellis Shepherd, Alex goes to see her since he is her emergency contact. He brings Meredith and her kids back to her house. She asks to move back in with him in her old house. Alex sells Meredith back the house and he and Jo rent a loft.
Alex and Jo continue to struggle with their relationship. Alex wants to settle down, marry Jo, and have kids. However, Jo continues to resist. When Karev proposes to her, Jo tells him she can't marry him, so he breaks up with her. Later, Alex realizes that he misses Jo and gets her back. They seem to be doing well for some time, until Alex brings up marriage again and the two fight, as Jo still continues to argue that she cannot marry him. Alex storms out, leaving their relationship uncertain. During Owen and Amelia's wedding, Alex realizes that even though she won't marry him, he loves Jo and goes back to her again. However, when he arrives at their loft, he finds Jo highly intoxicated, wearing nothing but her bra and underwear, and surgical intern, Andrew Deluca lying on top of her. Alex assumes that Deluca was attempting to take advantage of Jo while she was inebriated and is filled with rage. He beats Deluca to a pulp with his bare hands.
Andrew is badly injured, with his face bruised beyond recognition. He is unconscious and on the verge of dying. Alex realizes what he's done and quickly rushes Deluca to the hospital. There, the doctors call the police as they struggle to save Andrew and discover who did this to him. Alex lies to everyone and says that he found Andrew in this state and brought him to Grey Sloan. However, Ben Warren is suspicious of Karev. Meredith also quickly realizes that Alex was in fact the one who beat Deluca. She covers for him and the two continue to lie to everyone in the hospital about Alex's actions. Soon, Karev learns that Andrew wasn't doing anything wrong and that he had beaten up a good guy. Meredith decides that even though she loves Alex, she needs to turn him in. She goes to Bailey and tells her the truth. But, when the two rush to the police they find Alex being arrested for aggravated assault, as he had turned himself in. He is taken to jail and Meredith bails him out. While they wait for a trial, Bailey suspends Alex as an attending and makes him work in the clinic. Eventually, Jo finally tells Alex that the reason she couldn't marry Alex is because she is already married. Her husband is abusive and so she ran away and changed her name to Jo Wilson so that he wouldn't find her. Alex realizes that when Jo is called to the stand as a witness in the trial, this information about her past and lack of records under the name Jo Wilson may be revealed, and when the information goes public, her husband may find her. To keep her safe, he decides to take the plea deal without a trial, ensuring that he goes to jail for 2 years. However, when Alex tells Meredith this, she begs him not to and tells him that she can't lose him too because she's already lost everyone else important in her life. Alex struggles to decide whether or not to take the plea deal.
Meredith searches for Alex's case online, to find that the trial had been put off indefinitely. She assumes that he took the plea, and began calling and visiting various local jails to find him. After a full day of searching without finding him, she goes home to sleep, and discovers him sleeping in her bed. He explains he slept there all day.
except in the first part of season 13 i havent finished it yet so