The body produces stomach acid to help break down food for digestion, as well as to kill bacteria, and it is estimated that a person's body produces about 0.5 gallons (2 L) of the acid each day. The amount of stomach acid present in the average healthy human stomach at any given time ranges from about 0.66 to 3.38 fluid ounces (20 to 100 mL). If the stomach produces more acid than normal, it can lead to ulcers, which are painful sores on the stomach lining. As people age, their stomachs might produce inadequate amounts of acid, which can cause digestive difficulties.
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