A man's heavy coughing became so much he spit out an exact mold of his lung.

The 36-year-old man admitted into intensive care for heart failure experienced what doctors say was "an extreme bout of coughing" and out came a blood clot of his right bronchial tree, according to doctors who wrote about his case in the New England Journal of Medicine.

He had previously been outfitted with a pacemaker, but during the course of additional treatment at the University of California San Francisco Medical Center, he began coughing up blood and phlegm, the journal states.

The coughing became so intense that a six-inch wide blood clot was coughed up in one piece, according to The Atlantic.

"The patient was extubated 2 days later and had no further episodes of hemoptysis," or coughing up blood, the authors wrote.

It's possible the blood thinning medication prescribed to the man helped create the vividly red, tree-root-looking figure. The Atlantic writes: "After days of coughing up much smaller clots, Wieselthaler’s (the doctor's) patient bore down on a longer, deeper cough and, relieved, spit out a large, oddly shaped clot, folded in on itself."

The man died from complications of heart failure about a week later.