It is possible to take too much magnesium, asserts Healthgrades, but it is unusual to ingest an excessive amount of the mineral by consuming foods that contain magnesium. Magnesium overdose, referred to as magnesium toxicity or hypermagnesemia, results from ingesting large doses of magnesium supplements.
Mild magnesium overdose usually results in nausea and diarrhea, explains Healthgrades. If a person ingests large quantities of magnesium, symptoms can also include abdominal pain and swelling, muscle weakness and flushing of the skin. Hypermagnesemia can be fatal, and immediate medical care should be sought if an individual exhibits breathing difficulties, chest pain or heartbeat irregularities, severe abdominal or back pain, balance problems, confusion, or loss of consciousness.