What is the harm of inhaled e-cigarette oil?

E-cigarettes are harmful to health through heated liquid nicotine. Nicotine constricts blood vessels and increases blood pressure, but it also puts pressure on the heart. So e-cigarettes are harmful to health, because they can cause heart disease and stroke. The difference between e-cigarettes and traditional cigarettes is that the former may cause cancer and heart disease, while the latter may cause heart disease.