When Madonna was found unresponsive and had to be intubated at the intensive care unit, she seemed to be contending with sepsis — a life-threatening infection. The Centers for Disease Control and Prevention reports that every year, at least 1.7 million adults in the U.S. develop sepsis and nearly 270,000 die from it.

But what is sepsis exactly?

It’s a bacterial, viral, or fungal infection often associated with a dysfunctional immune system, widespread inflammation, blood clots, or leaky blood vessels, which can lead to severely low blood pressure and potential organ damage.

People ages 65 and over (Madonna is 65) and those with a compromised immune system who have recently had surgery, have a chronic condition such as obesity, or have an infection of the lungs, urinary tract, skin, or gastrointestinal tract are most vulnerable.

Symptoms include fever, chills, rapid breathing and heart rate, rash, confusion, and disorientation — making it easy to mistake sepsis for some other illness.

In the intensive care unit, doctors may administer antibiotics and fluids, drugs to support heart and blood vessel function and prevent blood clots, and in some cases insert a breathing tube or perform surgery to excise the infection.

Although the risk of death increases every hour treatment is delayed, about 80 percent of patients recover from sepsis — most with no residual problems.

However, sepsis can leave a person with cognition problems and make them more vulnerable to developing other infections.

If you or a loved one has those symptoms and are at risk, get to an emergency department ASAP.