You won’t be needing these to stay alive

One lung

You need at least one lung to breathe, but the other can be removed to treat lung cancer, tuberculosis, or other lung diseases. Breathing is harder but still possible when one of the organs is removed; patients lose about 35 per cent of the volume of air they can exhale in a second, according to a study in the journal Respiratory Care. “The lung is a fixed cavity in the chest, so it can’t really get bigger,” says Dr Julie Heimbach, a transplant surgeon and surgical director of liver transplantation at Mayo Clinic.


The large intestine might be removed to treat colorectal cancer or a bowel disease such as Crohn’s disease or ulcerative colitis, and the doctor might take the rectum out along with it. A surgeon would either connect a pouch made of small intestine to your anus so you can pass stools as usual, or divert waste from the small intestine to an opening created in the abdomen, which would empty into a bag outside the body, says Dr Heimbach. Patients might have more bathroom trips and typically need to change their diets to avoid diarrhea. Learn 10 other medical reasons you could have diarrhea.


Reproductive organs

While reproductive organs might be an important part of your love life, they aren’t necessary for survival. One study found a hysterectomy didn’t have any negative impact on women’s sex lives. Hormonal changes after ovaries are removed could create a loss of libido, though. For men, having just one testicle removed because of prostate cancer probably won’t affect their sex life much, says Dr Eric A. Klein, chairman of the Glickman Urological and Kidney Institute at Cleveland Clinic. “A single testicle is all that’s needed to produce testosterone (which is necessary for a sex drive),” he says. If both are removed, your libido would go down significantly, and you wouldn’t be able to produce sperm. Men often have temporary erectile dysfunction and incontinence after the prostate is removed, says Dr Klein.


Patients with bladder cancer or, on rare occasion neurogenic bladder (when a problem with the nervous system affects bladder control), will need the organ removed – and the prostate and lymph nodes or uterus, ovaries and possibly part of the vagina along with it, says Dr Georges-Pascal Haber, PhD, a urologist with Cleveland Clinic. Doctors use a piece of intestine to divert urine that used to be stored in the bladder. The intestine can either form a “neobladder” that pushes urine out through the urethra, an “Indiana pouch” that patients manually drain with a thin tube, or an “ileal conduit urinary diversion” that sends urine into a bag outside the body, says Dr Haber. Because a neobladder or Indiana pouch can’t sense when it’s full like the bladder does, patients might need to set alarms every three or four hours to remind them to empty it, but life will basically go back to normal. “They start to recognise when the bladder is full through hot flashes or different symptoms,” says Dr Haber.


The liver makes bile to break down fats, and that bile gets stored in the gallbladder in case you eat a particularly fatty meal – but your body doesn’t rely on that stored bile to break down foods. Most people have a steady enough diet that they won’t notice much difference when their gallbladder is gone, says Dr Heimbach. “They don’t need that extra bile because your body is used to your diet and knows how to digest it,” she says. “It might have been more important in the past, when we didn’t have such a steady diet.” Gallstones are the most common reason the organ would be removed.


With some weight-loss surgeries – and for aggressive stomach cancers that haven’t spread to other parts of the body – patients might have part or all of their stomach removed. Normally, the stomach absorbs vitamins and jump-starts digestion by mixing foods with acids to break them down. Once the stomach is gone, surgeons will connect the esophagus directly with the small intestine. After surgery, patients can still eat solid food, but they’ll only be able to handle smaller quantities and might need to avoid certain foods to avoid “dumping syndrome” when the food passes quickly into the small intestine, says Dr Abdullah Shatnawei, a gastroenterologist at Cleveland Clinic. “As food is dumped into the small bowel, sensations of dizziness, lightheadedness, sweating can occur, as well as bloating, satiety, fullness,” he says. They might also need a sudden trip to the bathroom.


The spleen’s main function is filtering blood, but it might be removed if it’s damaged or diseased, such as for the blood disorder, idiopathic thrombocytopenic purpura. Because it plays an important role in the immune system, patients are more likely to get sick once it’s removed. “We do have to give patients who are getting their spleen removed certain vaccinations because they are going to be more at risk for certain infections,” says Dr Heimbach.

One kidney

Even though kidneys are vital organs, people are able to donate a kidney. Why? Two kidneys have more than enough capacity to meet your body’s needs; you can still process waste effectively with just one. As long as a donor has healthy kidneys, “they will have reduced kidney function but still have more than they need to keep living,” says Dr Heimbach.


The function of the appendix isn’t totally clear. Some experts think it’s a useless organ that served a purpose for our ancestors, while recent research suggests it might be keeping “good” bacteria safe. For some people, though, it does more harm than good. “It does get blocked up and infected and has to be removed sometimes,” says Dr Heimbach. Even if it does play a role in immunity, there haven’t been any long-term health effects associated with getting an appendix removed.