News > 7 dangerous side effects of starting your day with black coffee

7 dangerous side effects of starting your day with black coffee

Drinking black coffee on an empty stomach can increase stomach acid production, leading to heartburn, indigestion, or even ulcers in people with sensitive stomachs. The caffeine in coffee can interfere with how your body handles insulin and glucose, causing sudden spikes and dips in your blood sugar levels. Drinking black coffee on an empty stomach can lead to dehydration. The caffeine in coffee can act as a diuretic, increasing urine production.