Related: Medical stop-loss insurance is trending up

They have also steadily increased every year, from 60 in 2012 to 107 in 2015. The number of claims exceeding $2 million, however, has not risen steadily, jumping from two to 20 in 2013 but then dropping again in the subsequent two years.

"By highlighting the conditions that create catastrophic claims and providing insights into trends influencing high costs, we can help employers anticipate what they'll see when self-funding and raise awareness about the importance of cost-containment resources and stop-loss insurance,” says Brad Nieland, vice president of Sun Life Financial’s stop-loss division, in a press release.

Related: Employees' health worries may be soothed by disability insurance

Here are the top 10 ailments associated with self-funded employer claims:

Sepsis can be life threatening, with 50 percent of all cases starting as infection in the lungs. (Photo: iStock)

10. Septicemia

A condition that arises when the body reacts violently to an infection, damaging critical organs in the process and in the most severe cases leading to septic shock, septicemia resulted in $54.7 million in reimbursements between 2012 and 2015, or 2.4 percent of the total.

Top causes of respiratory failure include lung diseases such as chronic obstructive pulmonary disease, pnuemonia, pulmonary embolism, and cystic fibrosis. (Photo: iStock)

9. Respiratory failure

Pulmonary collapse or respiratory failure was the ninth leading claim for self-funded employers, resulting in $55 million in reimbursements from stop-loss insurance policies. Risk factors for the condition include binge-drinking, smoking, and working in an environment that leads to inhalation of chemicals that irritate the lungs, all issues that employers can have a hand in improving.

Stroke is the leading cause of long-term disability in the United States with approximately 795,000 people suffering from a stroke each year. (Photo: iStock)

8. Cerebrovascular disease

Most commonly manifested through a stroke, cerebrovascular disease or blood brain vessels prompted $57.4 million in reimbursements between 2012 and 2015, for 2.4 percent of the total. Although strokes are the fifth leading cause of death for Americans, but two-thirds of stroke patients are over the age of 65, suggesting the burden of caring for stroke patients falls mostly on Medicare, rather than employers.

Affecting nearly 5 million Americans, heart failure is the only major cardiovascular disorder on the rise. (Photo: iStock)

7. Congestive heart failure

The condition that afflicts roughly 2 percent of the adult population and 5 percent of those age 60-69 resulted in $57.8 million in reimbursements from catastrophic insurance policies in 2012-15, accounting for 2.5 percent of the total.

One organ donor can save up to eight lives. That sounds like a lot, but still, 120,000 people are in need of an organ transplant in America. (Photo: iStock)

6. Transplants

Transplants are becoming more common than ever, but the good news is that the operations are not as likely to force catastrophic coverage. While transplants increased 65 percent between 2012 and 2015, the total amount of stop-loss reimbursements paid because of transplants only ticked up 0.7 percent compared to 2011-14, to $62.2 million.

According to the World Health Organization, an estimated 15 million babies are born too early each year. One million of those children die because of complications. (Photo: iStock)

5. Premature births/low birth weight

Babies that are born prematurely and have to undergo long hospital stays in incubators or other treatment can prompt astronomical costs for patients and their employers. From 2012 to 2015, employers received $75 million in reimbursements related to such costs incurred by employees, or 3.2 percent of the total.

Congential disorders, such as Down syndrome and spina bifida, affect 3 percent to 4 percent of all babies born in America. (Photo: iStock)

4. Congenital anomalies

The top claim that specifically relates to a condition at birth, congenital anomalies prompted $96.3 million in reimbursements from 2012 to 2015, holding relatively steady from the 2011 to 2014 period. That accounts for 4.1 percent of total reimbursements.

Kidney disease, sometimes treated with dialysis, affects 26 million Americans. Currently, 1 in 3 American adults is at risk for developing kidney disease. (Photo: iStock)

3. Chronic renal disease

Employers received $156 million from claims related to severe disease of the kidneys, accounting for 6.7 percent of the total. That is a 1 percent decrease from the 2011 to 2014 period. While the costs of treating the condition have decreased 21 percent in the past four years, the disease remains common and costly nonetheless. According to some estimates, chronic renal failure as much as 10 percent of the population, but it is the later stages of the condition that are the most severe and the most costly, often resulting in kidney transplants.

New cases of leukemia, lymphoma, and myeloma are expected to account for 10.2 percent of the more than 1.6 million new cancer diagnoses in 2016. (Photo: iStock)

2. Leukemia/lymphoma/multiple myeloma

The second family of cancers is the No. 2 claim for catastrophic insurance. Its financial impact is great, but much smaller. Employers received $188 million between 2012 to 2015 from stop-loss reimbursements related to these conditions, accounting for 8.1 percent of total claims nationally. The value of such claims has remained steady in recent years.

Breast cancer is a form of maligant neoplasm that affect 1 in 8 U.S. women. (Photo: iStock)

1. Malignant neoplasm

The leading type of cancer is by far the leading reason that employers make claims on their stop-loss policies. These types of cancer accounted for 18.5 percent of all stop-loss claim reimbursements from 2012 to 2015, the study found, totaling a whopping $429 million. That represents a 0.9 percent increase over the 2011 to 2014 period.