The disadvantage of coffee drinking is the stimulation to the nerve. Its function is just like the stimulant. Too much drinking will directly lead to insomnia, palpitation; tinnitus etc. furthermore, the blood pressure will be high in 12 hours after a cup of coffee drinking. Especially when you lose your temper, the coffee will increase your degree of the bad mood. You know coffee itself is not a drug and it could not do harm to your health, but when you in bad healthy of hypertension or get the anxiety disorder, you'd better not to drink coffee; even in your good condition of health, too much coffee's caffeine will also disorder your biological clock. The high blood pressure and insomnia and bad mood of course will damage your health with bloodshot and sore eyes.