When Nailah Winkfield took her daughter to Children 's Hospital & Research Center in Oakland , California , for a tonsillectomy , she thought it would be a short stay . `` When I walked her into that hospital , she was perfectly fine , '' Winkfield told CNN 's Piers Morgan . `` There was nothing wrong with her . She had no health problems . '' After the December 9 surgery , Jahi McMath , 13 , woke up and asked her mother for a popsicle . But a short time later , the teen started bleeding from her mouth and nose . Winkfield watched in horror as Jahi went into cardiac arrest . Doctors later declared Jahi brain-dead and told Winkfield they were going to take her off life support . Her parents are fighting the hospital 's decision , asking for just a little more time . `` The big question is , 'How in the world did this happen ? ' `` said CNN senior medical correspondent Elizabeth Cohen . `` You 're talking about a tonsillectomy , right ? '' Tonsillectomy is the third most common surgical procedure performed on children in the United States , according to the American Academy of Otolaryngology , after circumcision and ear tubes . While not as common in adults , tonsillectomy joins the list of other common surgical procedures , such as appendectomy , cholecystectomy ( gallbladder removal ) and cesarean section . But just because these surgeries are routine does n't mean they 're 100 % safe . There 's a reason the consent form you sign at the hospital is so detailed . While your surgeon may have successfully performed this particular procedure thousands of times , each patient is different . Your risk does n't change because the person who was on the operating table before you survived . `` The complications are very rare , '' said Dr. Albert Wu , director of the Center for Health Services and Outcomes Research at Johns Hopkins Bloomberg School of Public Health . But `` uncontrollable bleeding can happen in almost any surgery . In extreme cases , you can bleed out . '' In general , Wu said , the most common post-surgery complications are bleeding , infection and damage to nearby tissue . During a tonsillectomy , for example , surgeons are removing the tonsils , two oval-shaped pads , near the back of the throat . To do so , they must cut or burn away the tonsils , which could lead to a small artery being nicked . Usually surgeons will stop the bleeding by cauterizing it , Wu said , but some people do n't clot well . A 2003 study of more than 14,000 tonsillectomy and adenoidectomy patients in Germany examined the post-operative complications for these surgeries . ( An adenoidectomy removes the patients ' adenoids and is commonly done alongside a tonsillectomy . ) Bleeding occurred in about 3 % of the patients ; five needed a blood transfusion . Another study done in Europe in 2004 that included more than 33,000 tonsillectomy patients found about 1.3 % were delayed in being discharged or returned to the hospital in the 28 days after surgery . Eight patients received a blood transfusion . One death was reported during the study period . The statistics are slightly higher for other common surgical procedures . A study of 1,254 laparoscopic cholecystectomies done in the Netherlands found complications in 12 % of the patients . Yet the risk of death is still low ; a 1996 meta-analysis found the mortality rate for gallbladder removal was between .086 % and .74 % . Certain patients are at greater risk during general surgery than others , Wu said . Patients with pre-existing conditions such as heart , lung or liver problems are more likely to suffer from complications or die . `` The stress of surgery can be too much for you to be able to maintain ( your body 's ) equilibrium , '' Wu said . Obese patients are also at greater risk . A small study published in 2012 showed severely obese children undergoing tonsillectomies had an increased risk of complications during their surgeries . But what if the patient 's body is n't at fault ? What if it 's the surgeon who messes up ? Medical errors kill more than 200,000 people every year in the United States , according to a study published in September . Add them all up and `` you have probably the third leading cause of death '' in the country , Dr. Peter Pronovost , senior vice president for patient safety and quality at Johns Hopkins Hospital , told CNN during a 2012 investigation into common medical mistakes . 10 shocking medical mistakes . Wu said patients should tell their surgeons `` everything that they know about themselves , '' including their past experiences with surgery and anesthesia , whether they have any allergies , and if they 're prone to bruising or heavy bleeding . `` The question people should always ask is , 'Do I need this surgery ? ' `` Wu said . `` In some cases not having surgery is riskier than having the surgery ... but for many , many things , the surgery is quite discretionary . You have a choice . ''
Jahi McMath , 13 , was declared brain-dead after a tonsillectomy . Tonsillectomies are the third most common surgical procedure for U.S. children . They can be performed to remove tumors or treat other conditions that affect brain function. Patients should ask themselves if they really need the surgery , expert says .