Some of the side effects of magnesium include low blood pressure, diarrhea, and breathing problems. There are also some magnesium side effects that may impact the nervous system and the brain. Side effects are usually only present when a person has taken more magnesium than needed. It is also likely that a person will experience other types of problems if he or she becomes deficient in magnesium. This element is essential to a person's survival, but either too much or too little of it will usually do more harm than good.
Magnesium serves many important purposes inside the body, including maintaining a stable blood pressure and heartbeat. Most people get enough of it every day, because it is present in so many different foods, including tea, cocoa, and most dark green vegetables. Supplements are occasionally needed for people who do become deficient in magnesium, and they typically cause no problems if they are taken as directed. Any amount over 350 mg of magnesium in supplement form is considered too much, but a person should talk to his doctor to be sure of the amount he needs. If too much is taken, a person may experience side effects of magnesium.
Too much magnesium can have a negative impact on the heart, causing low blood pressure and an irregular heartbeat. The irregular heartbeat could be an irreversible problem if a person has taken an amount well over the recommended dosage and might result in death. Additionally, a person who does not have an adequate amount of magnesium in her system may also experience an irregular heartbeat. Gastrointestinal difficulties are other common side effects of magnesium and may include nausea, diarrhea, and vomiting if a person has taken too much. These problems also tend to result if a person is deficient in magnesium.
Other complications resulting from too much magnesium include respiratory problems, seizures, and sudden changes in a person's personality. Magnesium supplements may be helpful for people who suffer from ADHD (attention deficit hyperactivity disorder) and multiple sclerosis, and most over-the-counter antacids contain lots of magnesium. The fact that antacids contain magnesium and are often abused by many people might be a concern. People who take antacids more than a few times a day on a regular basis may need to either cut back on how much they take or see their doctor to determine if there is an underlying problem requiring excessive use of antacids. Overuse of antacids, laxatives, and other such related products may be one of the leading causes of magnesium overdose.