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Hypokalemia is when blood’s potassium levels are too low. Potassium is an important electrolyte for nerve and muscle cell functioning, especially for muscle cells in the heart. Your kidneys control your body’s potassium levels, allowing for excess potassium to leave the body through urine or sweat.
Hypokalemia is also called:
- hypokalemic syndrome
- low potassium syndrome
- hypopotassemia syndrome
Mild hypokalemia doesn’t cause symptoms. In some cases, low potassium levels can lead to arrhythmia, or abnormal heart rhythms, as well as severe muscle weakness. But these symptoms typically reverse after treatment. Learn what it means to have hypokalemia and how to treat this condition.
Mild hypokalemia usually shows no signs or symptoms. In fact, symptoms generally don’t appear until your potassium levels are extremely low. A normal level of potassium is 3.6–5.2 millimoles per liter (mmol/L).
Being aware of hypokalemia symptoms can help. Call your doctor if you are experiencing these symptoms:
- muscle cramping
Levels below 3.6 are considered low, and anything below 2.5 mmol/L is life-threateningly low, according to the Mayo Clinic. At these levels, there may be signs and symptoms of:
- respiratory failure
- breakdown of muscle tissue
- ileus (lazy bowels)
In more severe cases, abnormal rhythms may occur. This is most common in people who take digitalis medications (digoxin) or have irregular heart rhythm conditions such as:
- fibrillation, atrial or ventricular
- tachycardia (heartbeat too fast)
- bradycardia (heartbeat too slow)
- premature heartbeats
Other symptoms include loss of appetite, nausea, and vomiting.
You can lose too much potassium through urine, sweat, or bowel movements. Inadequate potassium intake and low magnesium levels can result in hypokalemia. Most of the time hypokalemia is a symptom or side effect of other conditions and medications.
- Bartter syndrome, a rare genetic kidney disorder that causes salt and potassium imbalance
- Gitelman syndrome, a rare genetic kidney disorder that causes an imbalance of ions in the body
- Liddle syndrome, a rare disorder that causes an increase in blood pressure and hypokalemia
- Cushing syndrome, a rare condition due to long-term exposure to cortisol
- eating substances like bentonite (clay) or glycyrrhizin (in natural licorice and chewing tobacco)
- potassium-wasting diuretics, such as Thiazides, loop, and osmotic diuretics
- long-term use of laxatives
- high doses of penicillin
- diabetic ketoacidosis
- dilution due to IV fluid administration
- magnesium deficiency
- adrenal gland issues
- poor absorption
- delerium tremens
- renal tubular acidosis types I and 2
- catecholamine surge, such as with a heart attack
- drugs such as insulin and beta 2 agonists used for COPD and asthma
- barium poisoning
- familial hypokalemia
Your risks for hypokalemia can increase if you:
- take medications, especially diuretics known to cause potassium loss
- have prolonged illness that causes vomiting or diarrhea
- have a medical condition like the ones listed above
People with heart conditions also have a higher risk for complications. Even mild hypokalemia can lead to abnormal heart rhythms. It’s important to maintain a potassium level of around 4 mmol/L if you have medical condition such as congestive heart failure, arrhythmias, or history of heart attacks.
Your doctor will usually discover if you’re at risk for or have hypokalemia during routine blood and urine tests. These tests check for mineral and vitamin levels in the blood, including potassium levels.
Your doctor will also order an ECG test to check your heartbeat since hypokalemia and heart abnormalities are commonly linked.
Someone who has hypokalemia and shows symptoms will need hospitalization. They will also require heart monitoring to make sure their heart rhythm is normal.
Treating low potassium levels in the hospital requires a multi-step approach:
1. Remove causes:After identifying the underlying cause, your doctor will prescribe the appropriate treatment. For example, your doctor may prescribe medications to reduce diarrhea or vomiting or change your medication.
2. Restore potassium levels: You can take potassium supplements to restore low potassium levels. But fixing potassium levels too quickly can cause unwanted side effects like abnormal heart rhythms. In cases of dangerously low potassium levels, you may need an IV drip for controlled potassium intake.
3. Monitor levels during hospital stay: At the hospital, a doctor or nurse will check your levels to make sure the potassium levels don’t reverse and cause hyperkalemia instead. High potassium levels can also cause serious complications.
After you leave the hospital, your doctor may recommend a potassium-rich diet. If you need to take potassium supplements, take them with lots of fluids and with, or after, your meals. You may also need to take magnesium supplements as magnesium loss can occur with potassium loss.
Hypokalemia is treatable. Treatment usually involves treating the underlying condition. Most people learn to control their potassium levels through diet or supplements.
Make an appointment with the doctor if you’re showing symptoms of hypokalemia. Early treatment and diagnosis can help prevent the condition from developing into paralysis, respiratory failure, or heart complications.
About 20 percent of people in hospitals will experience hypokalemia, while only 1 percent of adults not in the hospital have hypokalemia. A doctor or nurse will usually monitor you during your stay to prevent hypokalemia from occurring.
Seek medical attention if you are experiencing vomiting or diarrhea for more than 24–48 hours. Preventing prolonged bouts of illness and loss of fluids is important to keeping hypokalemia from occurring.
Eating a diet that is rich in potassium can help prevent and treat low blood potassium. Discuss your diet with your doctor. You’ll want to avoid taking too much potassium, especially if you’re taking potassium supplements. Good sources of potassium include:
- peas and beans
- peanut butter
While a diet low in potassium is rarely the cause of hypokalemia, potassium is important for healthy body functions. Unless your doctor tells you otherwise, eating a diet rich in potassium-containing foods is a healthy choice.
What’s the difference between prescription and over-the-counter potassium?
Prescription potassium supplements contain a much higher dose than over-the-counter supplements. This is why they are limited to distribution by prescription only. They should only be taken as prescribed by your doctor. Inappropriate administration can easily result in hyperkalemia, which is as dangerous as hypokalemia. You need to use caution and consult your doctor about taking OTC potassium if you have chronic kidney disease or you’re on an ACE inhibitor, angiotensin receptor blocker (ARB), or spironolactone. Hyperkalemia can develop quickly in these situations if you’re taking any type of potassium supplement.Graham Rogers, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.