Discussing Effects 1 - revised

After getting out of bed, some people drink a cup of coffee before having breakfast.  However, drinking too much coffee containing much caffeine may cause several problems.  For one thing, people may have a headache, and feel nervous and anxious, which lead to their suffering from insomnia that makes them sleep uncomfortably.  Moreover, a wave of nausea sweeps over people and caffeine brings about some gastrointestinal problems. Therefore, people having poor digestion can’t drink too much coffee, or they will feel painful.  Last but not the least, caffeine causes even fast or irregular heartbeat and muscle tremors.  To keep a healthy body, not to absorb too much caffeine is the best way.