A 60-year-old man, An, with a 40-year smoking history, experienced prolonged chest pain and was diagnosed with a heart attack.

Smoking can cause genetic mutations, disrupt the body's immune system, and lead to the formation of malignant tumors in the lungs.

A 23-year-old man experienced dizziness and weakness on one side of his body due to an ischemic stroke. He had no pre-existing medical conditions but had been smoking since he was 17 and regularly stayed up until 1 or 2 a.m.

I was just diagnosed with lung cancer, but I've never smoked. Why did I get this disease? (Nguyen Thi Mai, 54, Kien Giang)

A 50-year-old man, Man, suffered from a non-healing finger ulcer for a month. Doctors diagnosed him with blocked arteries in his right hand due to smoking.

After years of smoking two packs of cigarettes a day, 72-year-old Hai experienced leg pain and sought medical attention. Doctors discovered extensive damage to his blood vessels.