Read the following text from a student essay. How can the writer best improve their ideas and development?

Why is smoking cigarettes bad for your health? Cigarettes contain poisonous substances like carbon monoxide and tar, which can harm every part of your body. Smoking causes heart disease and damages your blood vessels. Eating a diet high in fat, sugar and salt can also lead to heart disease. A lack of exercise contributes to heart disease, too. Smoking damages your lungs and can cause breathing problems or lung cancer. In fact, it can cause cancer in any organ in your body.