A CT scan gives more radiation than a regular X-ray. How much more depends on the scan and the person, and the risk is small but uncertain.

Some cancers found by screening would never have made a person sick. This is called overdiagnosis. It is real, it is hard to see, and it does not mean screening is useless.

A very good test can still be wrong most of the times it says "positive." The reason is simple arithmetic about how rare a disease is.

Learn how to read scientific papers effectively. This guide breaks down key sections and offers strategies for understanding complex research.

Some journals charge scientists to publish but skip the expert checks they promise. Here is how they operate, how big the problem is, and how to tell a trusted journal from a fake one.

Science gets things wrong. What makes it different is that it has ways to find its own mistakes. Here is how that works, with real cases, and where it still falls short.