"It can be very embarrassing," said Jonas.
In 2006, Jonas also had a heart attack. Until now, he didn't know the two conditions were linked.
"I was very surprised," said Jonas. "I had no idea."
Cardiologist Dr. David Ancona says having psoriasis can double the risk of a heart attack.
"There are diseases that exist that, for some reason or another, seem to follow one another like a shadow," said Dr. Ancona.
One study showed women with endometriosis are 62-percent more likely to develop melanoma.
"It's becoming clearer to us that these diseases don't exist in isolation," said Dr. Ancona.
What's less clear is why some diseases shadow others.
"Certain diseases might be genetically linked," said Dr. Ancona.
Having just one migraine a month gives you a 50-percent higher risk of a heart attack. Having one a week gives you four-times the risk of a stroke. And having three of the five traits linked to metabolic syndrome increases the risk of kidney stones.
"The benefit of the patient knowing that they could be at risk for another disease would be that they'd be evaluated for that other disease," said Dr. Ancona.
Sam Jonas wishes he knew psoriasis raised his heart attack risk.
"Had I known that at that time, I probably would have gotten a stress test much earlier," said Jonas.
That step might have saved his heart. Instead, he'll take daily drugs to treat both conditions.
Having psoriasis or insomnia can also increase your chance of developing diabetes. And research shows that nearly half of those who have asthma also have a psychological condition -- like depression.