Smoking is a very bad habit. It is a very dangerous habit, too. It is so dangerous and mortifying that it may cause cancer, heartattack, high blood pressure, chronic lungs troubles and other serious diseases. Smoking tobacco products is a major health hazard. It is found that one puff of cigarette smoke contains fifteen billion particles of matter including nicotine, methyl alcohol, carbon monoxide, formaldehyde, arsenic, benzopyrene and several other acids. These are all really very fatal and injurious to our health. Nicotine constricts the size of blood-vessels which impedes the normal flow of blood and oxygen in the body. It causes the heart to beat faster. Benzopyrine, arsenic and tobacco tar are cancer-causing agents in animals and human beings. Tobacco tar forms a brown sticky mass inside the lungs and it hinders the easy flow of blood. The presence of carbon monoxide in the tobacco tar drives out the oxygen from the blood and it is also dangerous. Besides, smoking can cause irritation in the eye, offend the nose and unsettle the mind. After all, the dangers of smoking is quite unlimited and all should avoid it to live a happy and peaceful life.