When you hear of someone drinking themselves to death, most of us assume it's alcohol-related. But that wasn't the case for a 35-year-old man from the U.K., the Daily Mail reports.

An investigation into how Shaun McNamara died revealed that he drank himself to death after consuming too much water. His body was found on the floor of his bathroom last September.

At first, doctors thought McNamara had suffered a heart attack. It was not until an autopsy revealed that he had downed so much fluid, so fast, that his brain had swollen, the Mail reported.

"In 35 years as a pathologist I have never come across such a case," said Dr. Ian Reed, who carried out the autopsy.

Water intoxication, also known as hyponatremia, normally is linked to marathon runners' drinking too much water after a race. When this happens, there is so much water in the body that it dilutes vital minerals such as sodium down to dangerous levels. This can lead to confusion, headaches and in extreme cases fatal swelling of the brain, according to the report.

Click here for more on the story from The Daily Mail