Smoking tobacco is so harmful to the body that it changes a person's immune system, leaving them vulnerable to more disease and infection even years after they've quit, a new study found.Video above: ...

Smoking can damage the heart even in small amounts, and experts warn that the risks are higher for women. Studies show women who smoke face a 25% greater risk of coronary artery disease than men.

Smoking, and its harmful substances such as nicotine, can harm almost every part of the body, including the brain. It can also lead to other brain conditions, such as cancer, dementia, and stroke.

Ornithologists at the Natural History Museum and UCLA are studying how smoke from the January wildfires will affect the region’s birds. It’s part of a broader scientific effort to understand the ...