Drinking too much coffee can cause several side effects, including:

• Anxiety: High levels of caffeine can cause feelings of nervousness and anxiety.
• Insomnia: Caffeine can interfere with sleep, making it difficult to fall asleep or stay asleep.
• Digestive issues: Large doses of caffeine may lead to loose stools or even diarrhea in some people.
• Muscle breakdown: Ingesting large amounts of caffeine can cause rhabdomyolysis, or the breakdown of damaged muscle.
• Addiction: Caffeine can become habit-forming and trigger certain brain chemicals similarly to the way cocaine and amphetamines do.
• High blood pressure: Excessive caffeine intake can cause an increase in blood pressure.
• Headache: Too much caffeine can cause headaches.
• Irritability: High levels of caffeine can cause irritability.
• Frequent urination or inability to control urination: Caffeine is a diuretic, meaning that it helps your body get rid of extra salt and water by urinating more.

It is important to note that everyone metabolizes caffeine differently, and some people may be more sensitive to its effects than others. The Mayo Clinic recommends limiting caffeine intake to no more than 400mg per day for most people. However, some people may need to consume less caffeine due to pre-existing health conditions or medications they are taking.