This document discusses potential side effects of green tea, including risks during pregnancy from caffeine, catechins, and tannic acids. Drinking large amounts, more than 6 cups per day, can cause sleeplessness, irregular heartbeat, diarrhea, and other issues. Those with heart conditions or kidney disease should be cautious. While green tea provides many benefits, drinking too much or mixing with alcohol can potentially cause minor side effects. Overall, green tea does more good than harm for most people.