4. Causes various cancers including lung, oral, abdomen, kidney, bladder, and colon
5. Damages your heart
6. Damages your bones
7. Can cause infertility
8. More likely to get colds, flu, bronchitis, pneumonia, and asthma
9. Pregnant women who smoke harm their unborn baby
There are more, but you get the idea. Smoking harms your entire body and hurts those who breath in the second hand smoke. These are all very good reasons to stop smoking.