It affects the absorption of calcium and easily causes osteoporosis.

Caffeine-containing drinks and foods can cause nausea, vomiting, headache and rapid heartbeat when consumed in large quantities by pregnant women. Caffeine will also enter the fetus through the placenta, affecting fetal development; Caffeine will lead to an increase in abortion rate, so drink decaffeinated drinks;

Children should not drink coffee. Caffeine can excite children's central nervous system, interfere with children's memory and cause ADHD.

It is a risk factor for the formation of digestive tract ulcer;

Supplementing caffeine when you are nervous is helpful to improve your alertness, sensitivity, memory and concentration. But if you drink more coffee than you are used to, you will have the same dose of stimulants, which will cause tension. For people who are prone to anxiety, caffeine can cause symptoms such as sweating, palpitations and tinnitus. Caffeine, which aggravates hypertension, is often combined with other simple painkillers because of its analgesic effect. However, if you take a lot of caffeine for a long time, if you already have high blood pressure, using a lot of caffeine will only make your situation worse. Because caffeine alone can raise blood pressure, if combined with emotional tension, it will have a dangerous multiplier effect. Therefore, people at risk of hypertension should especially avoid drinking caffeinated drinks when working pressure is high. Some people who drink coffee all the year round think they are immune to the effects of caffeine, but this is not the case. A study shows that after drinking a cup of coffee, the blood pressure can rise for as long as 12 hours;