If you abuse them, they can cause long term problems for sure. You should really do more research if you have to ask this question, bro. But really, abuse of any drug can cause health problems. Look at the stats on tylenol. Tons of kidney failure cases each year. It's awful. So yes, steroids can be dangerous and if you have a pre-existing disposition for a certain health problem, it could make that worse. So the key is doing lab work. You can watch exactly what is going on. Steroids are never going to sneak up and kill you. We aren't talking about street drugs here. Its going to happen over the long term and there will be signs along the way. So if you check your labs, you'll know whats going on. If your levels go back to normal after your cycle, and you run moderate doses with time off, you can maintain your health. It's the older generation that was running high doses and never getting labs done that ended up with problems. Another factor I have seen, is guys that use steroids and mess with recreational drugs. Maybe it's these same guys that didn't get their labs done, but that combo has proven to cuase problems. If you don't have a Dr that you trust, check online at sites like Private Labs MD. They offer scripts for labs at a reasonable price