Drinking a small amount of coffee every day is generally not harmful to the body, but if you drink too much coffee, it may affect your sleep, cause gastrointestinal discomfort and affect your heart rate. 1. Impact on sleep: coffee contains a large amount of caffeine, which has the effect of excitation of the nerves, if you drink a lot of coffee for a long period of time, it will easily lead to overexcitement of the nerves, which will affect the sleep, and may even lead to insomnia. 2. Cause gastrointestinal discomfort: long-term excessive drinking of coffee is likely to lead to an increase in gastric acid secretion, causing some stimulation of the gastric mucosa, especially for patients with chronic gastritis and gastric ulcers, which can cause symptoms such as gastric acidity, gastric pain, gastric distension and so on. 3. Impact on heart rate: the caffeine in coffee will have an impact on the heart rate, which can easily lead to panic, sweating and other symptoms. It is recommended to avoid drinking a large amount of coffee every day and to avoid strong coffee.