Diuretic

• Caffeine is a known diuretic. It fills up the bladder faster and induces fecal elimination more quickly. Caffeine replaces the receptors that would normally facilitate drowsiness and sleep and slows nerve cell activity, making it hard for the body to rest.
  
  

Vomiting

• Large amounts of caffeine can cause high blood pressure and vomiting.
  
  

Blood Sugar Levels

• A person without diabetes can benefit from caffeinated and decaffeinated coffee, as it helps lower the risk of developing type 2 diabetes. For people already afflicted with diabetes, caffeine is not recommended. It spikes sugar levels in the blood, making it hard for diabetic patients to control their blood sugar.
  
  

Ketones and Diabetic Coma

• Caffeine in high dosages has been found to have the same effect as high ketones in the blood, which is dangerous to diabetics, as it can also lead to diabetic shock and/or coma.
  
  

Gastrointestinal Tract

• Caffeine causes bloating and pain associated with too much gas. Sometimes the fermented waste products are absorbed back into the bloodstream instead of being eliminated. Toxins that stay in your gastrointestinal tract can lead to a higher risk of disease.