What is Hypomagnesemia?
Magnesium is an important nutrient that does a lot in our bodies, including helping with cell functions, nerve signaling, and more. Normal levels of magnesium in the blood are between 1.46 and 2.68 mg/dL. Hypomagnesemia, which is when your blood magnesium levels drop below 1.46 mg/dL, doesn’t usually cause symptoms until the level drops below 1.2 mg/dL.
Several things can lead to hypomagnesemia, including chronic illnesses, alcohol abuse, loss from the digestive system, loss from the kidneys, and other conditions. If you have hypomagnesemia, you might experience light shaking and a general feeling of weakness. In severe cases, it can cause a condition where the heart muscle doesn’t get enough blood supply and, in extreme cases, it could even lead to death.
What Causes Hypomagnesemia?
Hypomagnesemia, which is low levels of magnesium in the blood, may occur due to various reasons. One reason could be not taking enough magnesium in your diet. This can happen if you’re not eating much because you’re starving, battling an eating disorder like anorexia nervosa, or if you have a severe illness such as advanced cancer or are critically ill and on intravenous feeding.
Drinking a lot of alcohol can also reduce magnesium levels, with about 30% of people with alcohol use disorder having this problem.
Certain medications can also decrease magnesium levels. These include certain water pills (loop and thiazide diuretics), stomach acid reducers (Proton pump inhibitors), certain antibiotic types (Aminoglycoside antibiotics), antifungal drugs like Amphotericin B and Pentamidine, heart medication (Digitalis), chemotherapy drugs like cisplatin and cyclosporine, drugs that target growth factor receptors (cetuximab, matuzumab, panitumumab), and abusing laxatives.
Sometimes, a low blood magnesium level happens because the body moves magnesium into its cells from blood. This can occur in several situations, like when insulin is used to treat high blood sugar in people with diabetes (diabetic ketoacidosis), during the treatment of people who’ve been starving (refeeding syndrome), severe pancreas inflammation (acute pancreatitis), and when someone stops drinking alcohol suddenly (ethanol withdrawal syndrome).
Lastly, Hypomagnesemia can occur because of excessive magnesium loss from the gut or kidneys. This could happen due to severe diarrhea (acute or chronic), special diseases like Crohn’s disease or ulcerative colitis, taking too much magnesium by the bones after specific surgeries (Hungry bone syndrome), and certain genetic disorders that relate to how your body handles magnesium.
Additionally, losing more magnesium than usual can happen after stomach bypass surgery and kidney problems resulting from kidney transplant, healing from severe kidney damage (acute tubular necrosis), and when urine production increases after a blockage has been removed (postobstructive diuresis).
Risk Factors and Frequency for Hypomagnesemia
Hypomagnesemia, or low magnesium levels, is a health issue that affects a varying amount of people based on factors like their health condition and environment. In the general population, between 2.5% and 15% of people have been found to have hypomagnesemia. This percentage increases for people who are in the hospital, ranging from 12% to 20%. People who are critically ill see the highest percentages, with about 65% of them having hypomagnesemia according to one study.
- Hypomagnesemia is found in 2.5% to 15% of the general population.
- For hospitalized patients, the range is higher, from 12% to 20%.
- People who are critically ill have the highest prevalence, with around 65% experiencing hypomagnesemia in one study.
- A study of 100 critically ill children, with an average age of 4.9 years, in a pediatric intensive care unit in India found a prevalence of about 55%.
- In patients with chronic alcohol use disorder, researchers found a 30% prevalence.
There hasn’t been any recent research that identifies which age groups are more likely to have hypomagnesemia.
Signs and Symptoms of Hypomagnesemia
When people have low levels of magnesium in their bodies, it can cause a range of symptoms. These can be grouped into three main categories: neuromuscular symptoms, cardiovascular symptoms, and other symptoms related to electrolyte and hormone imbalances.
Early signs of low magnesium (also known as hypomagnesemia) can include feelings of nausea, vomiting, not feeling hungry, feeling tired, and an overall sense of weakness. Other symptoms, such as difficulty swallowing and muscle weakness, can also occur.
Neuromuscular Symptoms
- Excessive nervous system activity, often the first sign that something’s wrong
- Shaking or tremors
- Muscle spasms, cramps, or a condition known as tetany, even when there’s no lack of calcium or alkalosis (having too many bicarbonates in your blood)
- Choreoathetosis (a condition that involves involuntary movements)
- Seizures
- Uncontrolled eye movement
- Feeling indifferent or apathetic
- Delirium or severe confusion
- Depression
- Agitation
- Psychotic episodes
- Coma
Cardiovascular Symptoms
- Changes in EKG readings
- Early or irregular heart beats
- A heart condition known as atrial fibrillation
- Life-threatening heart rhythms, including torsades de pointes
- Heart ischemia (reduced blood flow to the heart)
- Increased risk of digoxin toxicity, which is a complication of a drug used to treat heart conditions
Other Symptoms
- Low calcium levels, especially when magnesium levels are very low
- Lowered parathyroid hormone levels, which can affect calcium and phosphorus balance
- Low potassium levels (in about 60% of cases)
Serious cases of low magnesium have been reported to cause symptoms like loss of motor coordination, general convulsions, uncontrolled eye movement, and a rapid heart rate.
Testing for Hypomagnesemia
If your doctor suspects you might have low magnesium levels, also known as hypomagnesemia, they’ll likely do some tests. These include:
– Checking your blood for your magnesium, phosphate, and calcium levels.
– A basic metabolic panel, which measures different chemicals in your blood, such as your kidney function and glucose (sugar) levels.
– An electrocardiogram, which is a test that measures the electrical activity of your heartbeat to check for any heart rhythm problems.
While there’s currently no direct test for “ionized” or freely moving magnesium in your blood, your doctor can estimate whether your magnesium is too low by checking how much magnesium your body gets rid of in your urine over 24 hours.
If you do have low magnesium levels, your doctor will usually try to find out why from your medical history. They may also check for certain physical signs during an examination, such as involuntary eye movement (nystagmus) and muscle spasm (tetany). They can look for two specific signs of magnesium deficiency:
– Chvostek sign: This is where a tap on your facial nerve causes your facial muscles to twitch.
– Trousseau sign: This is a type of muscle spasm in your hand and wrist that can happen when a blood pressure cuff on your arm is inflated.
If the amount of magnesium your body gets rid of in your urine is above 2% and your kidney function is normal, it could mean your low magnesium levels are due to your body not holding onto magnesium as it should. This could be caused by certain drugs, such as diuretics (water pills), aminoglycosides (a type of antibiotic), or cisplatin (a chemotherapy drug).
If you have a family history of low magnesium levels, symptoms that can’t be explained, or the condition is identified early in infancy, your doctor may suggest genetic testing. This can check for specific gene mutations that cause various genetic disorders known to cause low magnesium levels, such as Gitelman syndrome, Bartter syndrome type 4, EAST syndrome, and Hypomagnesemia with secondary hypomagnesemia. These disorders can lead to various symptoms and complications.
Treatment Options for Hypomagnesemia
Hypomagnesemia, or low levels of magnesium in the blood, is treated differently based on the individual’s kidney function, the intensity of the symptoms, and overall health stability. While intravenous magnesium treatments may be designed for those in critical situations, individuals without severe symptoms who are not in the hospital might be able to take orally administered medications.
If you are experiencing no symptoms of hypomagnesemia and are not in the hospital, you might be prescribed an oral medication that slowly releases magnesium, such as magnesium chloride or magnesium L-lactate. After the treatment, your blood electrolyte levels will be checked to confirm that the treatment has been effective. It’s important to know that while the amount of magnesium in your blood may increase quickly with treatment, the amount of magnesium within cells may replenish more slowly. Therefore, if your kidneys are working correctly, you may need to continue magnesium treatment for 2 days after your blood levels have normalized.
However, caution is required for people with abnormal kidney function. In these cases, lower magnesium doses are recommended and should be closely monitored, as these individuals may be at risk of hypermagnesemia, or too much magnesium in the blood.
Incorporating certain foods rich in magnesium can also be beneficial while you’re taking supplements. Some of these foods include Halibut, Almonds, Cashews, Spinach, and Oatmeal.
If hypomagnesemia persists, addressing and treating the root cause is crucial. For instance, if you constantly have low electrolyte levels due to kidney difficulties, a diuretic called amiloride, which helps your body retain potassium and magnesium, may be beneficial.
In cases where low calcium levels (hypocalcemia) accompany hypomagnesemia, it is crucial to replenish your calcium levels before starting magnesium treatment. This is to avoid increased urinary excretion of calcium caused by the interplay between calcium and the sulfate present in magnesium sulfate. Additionally, potassium-sparing diuretics (like amiloride or triamterene) may be considered for individuals with hypomagnesemia caused by diuretic use or chronic kidney-related magnesium loss.
What else can Hypomagnesemia be?
When dealing with low magnesium levels, or hypomagnesemia, it’s always essential to check for other imbalances involving electrolytes. This is because low magnesium can cause a decrease in potassium and calcium levels. Moreover, various other electrolyte and hormonal irregularities can show similar symptoms. The following conditions exhibit signs that may resemble hypomagnesemia, so it’s important not to confuse them:
- Hypoparathyroidism (this can be due to genetics or unknown causes)
- Acrodysostosis
- Pseudohypoparathyroidism
- Blomstrand chondrodysplasia
What to expect with Hypomagnesemia
The outlook for low magnesium levels, or hypomagnesemia, largely depends on the reason behind the condition. If there’s an identifiable cause for this drop in magnesium, patients usually have a good chance of full recovery.
However, it’s more serious for critically ill patients. In these cases, low magnesium levels are linked with a longer stay in the intensive care unit, a higher likelihood of death, and an increased need for mechanical aid to breathe.
Possible Complications When Diagnosed with Hypomagnesemia
It is crucial to treat hypomagnesemia or low magnesium levels in the body. Extremely low levels of magnesium can potentially lead to deadly heart rhythm problems, like torsades de pointes, which is a specific type of fast and irregular heartbeat. If a person with an acute heart attack has hypomagnesemia, they are at a higher risk of experiencing these irregular heart rhythms within the first day after the heart attack. Additionally, low magnesium levels can lead to a condition called chondrocalcinosis, which is characterized by calcium buildup in the joints.
Main Risks of Low Magnesium Levels:
- Deadly heart rhythm problems
- Increased risk of irregular heart rhythms for heart attack patients within the first day
- Chondrocalcinosis or calcium buildup in the joints
Preventing Hypomagnesemia
If patients are repeatedly experiencing low levels of magnesium in their blood, known as hypomagnesemia, it’s recommended for them to include foods in their diet that are rich in magnesium. Specifically, such foods as listed above can help maintain the necessary levels. Patients should also get help from medical experts for any ongoing health conditions that may be the underlying cause of their low magnesium levels. Additionally, for those who consume alcohol on a regular basis, it’s advisable to limit its consumption as it can contribute to hypomagnesemia. So, a healthy diet and lifestyle changes can significantly help manage this condition.
