When you smoke, you feel stimulated, as your heart rate, blood pressure and hormone levels increase. Your body needs more of certain vitamins and minerals to cope with this stimulation, which is a form of stress. Cigarettes are expensive, highly addictive, and cause major and minor illnesses. Trying to quit is difficult for most people. All these factors add up to physical and emotional stress.
Caffeine is also a physical stressor.
It speeds you up for as long as 20 hours. Its effects are different in different people. For example, for some people it causes headaches, and for others, it relieves them. Caffeine can cause symptoms such as sleeplessness, upset stomach, increased blood pressure, and in women, breast lumps. Withdrawal can include severe headaches, nervousness, grouchiness, and rapid heartbeat.