But the teenagers are encouraging each other, as they manage their serious medical conditions.
Eighteen-year-old Tyler Weitz has muscular dystrophy and that has weakened his muscles. But his rare Becker muscular dystrophy also attacked his heart.
"I had to use a walker to help me walk," he said.
His brother, 15-year-old Austin, also has muscular dystrophy. It attacked his heart, too.
"It's very hard to be going through this," Austin said.
"It's hard mentally and physically and emotionally," Tyler added.
Six family members have had this rare muscular dystrophy. Many died young.
"If I would have known, I wouldn't have had children. I love my children -- don't get me wrong -- but if I had known that this is what we were gonna have to deal with, I wouldn't have had children," their mother Jennifer Banks said. "I didn't know until my brothers were diagnosed and what the whole family history thing was."
Two years ago, Tyler went into heart failure. He was saved with a heart pump.
"Then I felt horrible, and today I feel wonderful," Tyler said.
His little brother was watching.
"I knew I was gonna go through the same thing, so I just like when he was going through it, I like cried every single day," Austin said.
Austin got his heart pump in June. Both are doing well. Their surgeon says the pumps will lengthen their life and add ...
"Quality of life as they'll be able to exercise pretty much like a normal kid," said Methodist Heart surgeon Dr. Mattias Loebe.
"I know it's gonna give me a second chance at life. If I didn't have it, I would be on my deathbed and die," Austin said.
Now Tyler teaches Austin how to change the batteries. And they tease their mother by setting off the emergency warning.
They laugh, and for a while forget the rare disorder that has destroyed both of their hearts, and instead, feel like they're just teenagers, just brothers.
This rare type of muscular dystrophy is uncharted territory for the teens and their doctors. But the new heart pumps are giving them energy. And doctors say being active is the best thing they can do because that slows the progress of the muscular dystrophy.