Although lemon juice side effects are usually minor, drinking large quantities of this juice can cause some problems. These include heartburn, increased tooth sensitivity, diarrhea and allergic reactions. Lemon juice, like all citrus fruits, contains citric acid, and it is the acid that may cause problems when you drink a lot of lemon juice.

Heartburn

Although a relatively weak acid, citric acid is nevertheless an acid. Citric acid can irritate the esophagus and cause the burning sensation known as heartburn.

Increased Tooth Sensitivity

Acids of any kind can cause the erosion of tooth enamel. The enamel is what protects the nerves of the teeth, and if the enamel becomes thin, you may find your teeth are more sensitive to cold or to being brushed.

Diarrhea

Some people can develop citric acid intolerance. This is not an actual allergy, but your body’s negative response to a food substance. Diarrhea is one symptom of citric acid intolerance

Allergic Reactions

The most potentially serious of all lemon juice side effects is an allergic reaction to the citric acid. An allergic reaction is caused by your body’s immune system, which treats the offending food as an invader and tries to destroy it. You may develop hives, facial swelling, nausea or a severe drop in blood pressure. In its most acute form, an allergy can produce anaphylaxis, a condition that can be life-threatening in a few minutes if not treated immediately. If you are determined to have citric acid allergy, you will need to avoid citric acid in all forms, including lemon juice.