human
Is it true that if you drink too much coffee you'll start yawning a lot and get headaches?
assistant
Yes, caffeine is a stimulant. It can cause increased heart rate, anxiety, insomnia, restlessness, tremors, irritability, dizziness, confusion, and headaches. Drinking too much caffeine can also lead to physical dependence and withdrawal symptoms like fatigue, headache, nausea, and difficulty sleeping. So it's best to limit your caffeine intake to avoid these negative effects.