Green mountains and green waters tea itself is harmless, but excessive drinking tea or improper drinking methods may bring adverse effects on health, including:

1. Excessive drinking may lead to excessive caffeine intake in tea, causing discomfort such as palpitation, insomnia and headache.

2. Excessive drinking tea for a long time may lead to oral ulcers, yellow teeth and bleeding gums.

3. Tea contains some substances, such as oxalic acid and deoxyribonucleic acid. Long-term excessive drinking will increase the burden on the stomach and cause gastrointestinal discomfort.

4. If the water temperature is too high when drinking tea, it is easy to destroy the nutrients in tea and damage the esophagus and gastric mucosa. Long-term drinking may cause gastrointestinal adverse reactions, such as stomach pain and nausea.

5. Tea contains a certain amount of tannic acid. If you drink it improperly, such as drinking it on an empty stomach, it may stimulate the gastric mucosa, leading to problems such as stomach pain and indigestion.

To sum up, it is healthy to drink high-quality tea in moderation, but we need to pay attention to the way and quantity of drinking to avoid adverse effects.