Potassium is an important mineral that plays vital roles in the human body. It is classified as an electrolyte because it conducts electricity when dissolved in water. About 98% of the potassium in your body is found inside cells, while the other 2% is found in blood and fluid outside of cells.
Potassium helps regulate fluid balance, muscle contractions, and nerve signals. It also reduces blood pressure by blunting the activity of angiotensin II, a protein that causes salt retention, which in turn increases blood pressure. A low potassium level is called hypokalemia. This condition can cause a range of symptoms from minor to severe, depending on how low your potassium levels are.
What causes low potassium?
Some common causes of hypokalemia include:
- Inadequate potassium intake – Not eating enough potassium-rich foods like fruits, vegetables, beans, dairy, fish, and meat can lead to low blood potassium levels over time.
- Vomiting and diarrhea – Losing fluids that contain potassium through prolonged vomiting, diarrhea, or sweating can deplete potassium stores.
- Some medications – Medicines like diuretics, laxatives, steroids, and antibiotics can lower potassium levels by increasing mineral losses from the body.
- Diseases – Medical conditions like kidney disorders, hyperaldosteronism, and diabetic ketoacidosis can affect how the body handles potassium.
- Alcoholism – Long-term alcohol abuse interferes with how the kidneys conserve potassium.
Low potassium levels usually develop over time, but in some cases they can drop suddenly and severely in response to taking certain medications, trauma, surgery complications, or magnesium deficiency.
Mild symptoms of low potassium
As potassium drops, some of the earliest symptoms are:
- Muscle cramps and spasms
- Weakness or tiredness
- Constipation
- Abdominal discomfort or bloating
- Palpitations or abnormal heart rhythms
- Tingling or numbness
- Nausea
- Frequent urination
These mild signs are nuisances but usually resolve when potassium levels are restored. The muscle issues and tiredness stem from potassium’s role in muscle and nerve function. The heart rhythm changes occur because potassium helps conduct electrical impulses.
Moderate hypokalemia symptoms
As low potassium progresses to moderate deficiency levels, symptoms become more pronounced and prolonged:
- Muscle cramps, twitches, stiffness, or paralysis
- Heart palpitations
- Weakness making daily tasks difficult
- Bone fragility
- Breathing difficulties
- Digestive issues like abdominal pain, vomiting, constipation
- Kidney problems like frequent urination, kidney stones
- Hormonal disturbances
- Mental confusion, memory problems, hallucinations
The moderate symptoms interfere with normal activities and health. Medical care is often needed to treat the electrolyte imbalance and prevent complications.
Severe low potassium symptoms
When potassium drops substantially below normal levels, it can become a medical emergency. Signs of a severe deficiency include:
- Severe muscle weakness, temporary paralysis, respiratory failure
- Abnormal heart rhythms, low blood pressure, chest pain, heart attack
- Metabolic acidosis
- Kidney failure
- Psychosis, delirium, seizures, coma
- Intestinal paralysis or ileus
If left untreated, severely low potassium can be fatal due to its effects on muscles, kidneys, and the heart. Seek immediate medical attention if you experience any of the severe symptoms.
Why does low potassium make you feel weird?
The strange feelings associated with low potassium occur because it plays so many crucial roles in the body. Here’s a closer look at why hypokalemia causes such bizarre symptoms:
Muscle dysfunction
Normal muscle contraction and relaxation depends on potassium levels being in the right range. Low potassium allows excess sodium to enter muscle cells, causing depolarization and interference with signals between nerves and muscles. You might feel weak, shaky, or unable to control your muscles.
Numbness and tingling
Potassium is needed for transmitting signals along sensory nerves from parts like the skin, muscles, and extremities. Low levels disrupt these nerve impulses, leading to tingling, numbness, and reduced sensation.
Heart rhythm changes
The heart relies on coordinated electrical signaling to maintain a steady heartbeat. Low potassium alters electrical conduction in the heart, leading to abnormal heart rhythms like atrial fibrillation or possibly cardiac arrest.
High blood pressure
Potassium acts as a natural diuretic and vasodilator, lowering blood pressure. With inadequate potassium, blood pressure rises. Increased blood pressure further strains the cardiovascular system.
Kidney problems
Healthy kidneys regulate potassium balance by excreting excess and conserving supplies when low. Kidney dysfunction leads to poor potassium handling. Likewise, low potassium impairs kidney function and alters urine output.
Gastrointestinal distress
Slowed muscle contractions in the digestive tract cause bloating, nausea, constipation, and abdominal discomfort when potassium is deficient.
Mental confusion
Potassium is needed for generating electrical signals in the brain and nervous system. Depletion can impair neuron function, leading to memory problems, hallucinations, and altered mental status.
Bone weakness
Normal bone remodeling requires adequate potassium levels. Long-term deficiency leads to reduced bone mineral density and greater fracture risk.
Hormone disruption
Potassium influences release of hormones like insulin, aldosterone, and cortisol. Low levels throw these hormones out of balance, with widespread effects.
When to see a doctor
Consult your doctor promptly if you experience muscle spasms, heart palpitations, frequent urination, weakness, or mental confusion – especially if you have risk factors like taking diuretics or kidney disease. Let your doctor know about all medications and supplements, as these may be adjusted to resolve hypokalemia.
Seek emergency care for severe symptoms like muscle paralysis, chest pain, arrhythmias, or difficulty breathing. These require IV potassium replacement to stabilize potassium levels.
Diagnosing low potassium
Doctors can diagnose hypokalemia through:
- Medical history and symptom review
- Physical examination
- Blood tests to measure potassium – Normal range is 3.5-5.0 mmol/L
- Electrocardiogram to check heart rhythms
- Urine test for potassium
- Checking acid-base balance
- Blood magnesium levels
Your doctor will also check for any underlying condition causing potassium deficiency, like kidney disease, hyperaldosteronism, vomiting, or medication side effects.
Treating low potassium
Treatment depends on the severity of your potassium depletion. Options may include:
- Potassium supplements by mouth or IV drip to restore levels
- Medication changes if drugs are causing deficiency
- Treating any underlying condition, like kidney disorders, contributing to hypokalemia
- Changing diuretic type or dosage if they are resulting in excessive potassium losses
- Consuming more potassium-rich foods if deficiency is due to poor intake
- IV fluids and electrolyte replacement for low potassium from prolonged vomiting, sweating, or diarrhea
- Possible potassium-sparing diuretics
- Treatments for heart rhythm abnormalities if present
Lifestyle measures like eating potassium-rich foods, staying hydrated, and doing regular activity can help restore normal potassium status. Follow-up testing helps ensure levels remain in the normal range.
Preventing low potassium
You can take these steps to avoid becoming potassium deficient:
- Eat plenty of fruits, vegetables, beans, lentils, nuts, seeds, whole grains, dairy, fish, and lean meats.
- Avoid excessive alcohol and caffeine.
- Stay hydrated by drinking water.
- Take potassium supplements if at risk and approved by your doctor.
- Have bloodwork periodically to catch deficiency early.
- Be cautious with salt substitutes high in potassium if you have kidney disorders.
- Talk to your doctor before taking any new medications or supplements that might affect potassium.
Careful monitoring of medications and kidney function helps prevent hypokalemia – especially in those taking diuretics or digoxin. Seeking prompt treatment at the first signs of muscle cramps, weakness, or heart palpitations can also stop potassium depletion from worsening.
Conclusion
In summary, low potassium, also called hypokalemia, stems from inadequate dietary intake, vomiting/diarrhea, kidney disorders, medications, and other medical conditions. It can cause an array of unpleasant, sometimes severe symptoms due to potassium’s vital roles in muscles, nerves, heart activity, blood pressure regulation, kidney function, and hormones. Mild symptoms include fatigue, stomach issues, and muscle cramps. More serious signs are heart rhythm abnormalities, paralysis, and mental confusion. Prompt diagnosis via blood tests and treatment with potassium supplementation and diet changes usually resolve hypokalemia. Preventing deficiency through healthy food choices and monitoring medications/kidney function is key, along with early intervention when any muscle weakness, spasms, or heart palpitations develop.
