Lemons are highly acidic citrus fruits. If a person consumes lemon juice frequently and in excess, they may experience dentinal hypersensitivity and tooth decay because of the acidic nature of lemon.
Lemon juice may damage tooth enamel if drank in excess. Use a straw and rinse your mouth with plain water after drinking lemon water to reduce this risk.
Some people with GERD or acid reflux find lemon juice acidic. If you suffer acid reflux, see a doctor before drinking lemon water.
The high acidity of lemon water may induce heartburn, indigestion, and upset stomach in certain individuals. Lemon water is best in moderation for acid-sensitive people.
Lemon increases urine output as a diuretic. Some individuals benefit from this, but excessive ingestion without enough water might dehydrate them.
After applying lemon juice to the skin, sun exposure might trigger phytophotodermatitis. This may cause redness, inflammation, or blistering.