 Some people increase their chances of needing a transplant organ by leading what they know to be unhealthy lifestyles. Many of those who smoke, or drink alcohol excessively, or eat too much know that they are acting unhealthily (whether or not they know that smoking increases the risks of heart and lung failure, that drinking increases the risk of liver failure, and that obesity increases the risk of kidney and pancreas failure). It has been suggested that such people forfeit or weaken their claims to medical treatment (Brown 2013; Buyx 2008; Smart 1994; Walker 2010).