A new study found that three out of four Americans are not qualified to be kidney donors, even if they volunteer, due to health and financial reasons.

Study leader Dr. Anthony Bleyer worked with his colleagues from Wake Forest School of Medicine in identifying the causes of the kidney shortage. There are 102,000 people who are currently waiting for kidney transplants, and 3,000 are being added on the waiting list each month. However, the National Kidney Foundation website shows that only 17 percent of the patients had kidney transplants last year.

The researchers began their analysis by determining the number of people that are qualified to donate one of their kidneys. They used the qualifications that are similar to the transplant centers requirements. The team also looked at the medical data of the participants of an earlier national survey and their annual income to compute for the possible donors.

The analysis showed that based on health conditions of those with ages 21 to 70, obese and heavy drinkers are not eligible to be kidney donors, as well as those with diabetes, skin cancer, high blood pressure, HIV and heart diseases. Those with an annual income of less than $25,000 are also disqualified as they cannot opt to go on leave without pay for two to three weeks during recovery, according to Healthday News.

The researchers concluded that almost 75 percent of the U.S. population is not qualified to be kidney donors when both health and financial reasons are considered.

"I think the take-home message is, as a population, the healthier we are, the better we would be able to deal with many health problems, and the more donors there would be," Bleyer told Healthday News.

The study is not yet published in any peer-reviewed journal. Bleyer presented the findings on Nov. 15 at the American Society of Nephrology meeting in Philadelphia.