Can Blood Pressure Variations Be the Side Effects of High Potassium? Connections and More

Causes of high potassium in adults 

There are many reasons why potassium levels might be elevated. Below, we address some common causes (5). 

Pseudohyperkalemia

The most common reason for high potassium levels is pseudohyperkalemia. Pseudo means fake, and this describes a scenario when your laboratory tests indicate a high potassium level, while it is, in fact, normal.

This typically occurs due to poor blood draw technique or the blood sample being left out for too long, which causes the red blood cells to burst and release potassium. However, pseudohyperkalemia is nothing to worry about and is typically resolved with a new blood draw. 

Kidney disease

When your kidneys aren’t working properly, your potassium level can get too high. People with severe kidney disease have trouble clearing potassium from their blood, a major function of the kidneys. 

These individuals should try to avoid eating too many potassium-rich foods. Some examples include beet greens, chard, potato, yam, spinach, guava, and banana (6). In fact, you might hear the term renal diet, which describes safe diets for people with kidney disease. 

Fortunately, consuming or taking too much supplemental potassium usually does not cause hyperkalemia in adults with normal kidney function. That’s because their kidneys are capable of removing excess potassium from the bloodstream. 

Muscle injury

Muscle cells contain lots of potassium. When the muscle is damaged from accidents or trauma, cells release potassium into the blood. Exercising too hard without drinking enough water can sometimes injure muscle cells, leading to hyperkalemia. 

Insulin deficiency

Insulin is a hormone that regulates blood sugar levels. It also acts like a key that unlocks the doors of cells, allowing potassium to enter from the bloodstream. When there is not enough insulin or it is not functioning properly, more potassium remains in the bloodstream. This can occur when diabetes leads to severe complications, such as diabetic ketoacidosis. 

Sepsis

Bacteria in the blood is concerning. It can lead to a life-threatening condition called sepsis. In sepsis, your blood pressure can become very low, leading to less blood carrying oxygen to your tissues and removing carbon dioxide. When this happens, the blood becomes very acidic. Acidic blood causes potassium to leave cells and enter the bloodstream, leading to hyperkalemia. 

Tumor lysis syndrome

Chemotherapy can save lives for people who have cancer. Unfortunately, the damage it does to cancer cells can have unintended consequences. The drugs used in cancer therapy can cause cancer cells to burst and dump potassium into the blood. This condition is called tumor lysis syndrome. It is a medical emergency and can lead to other severe problems, such as low calcium levels and kidney failure. 

Medications

An important hormone called aldosterone helps the kidneys eliminate potassium from the body. Some medications act as enemies of aldosterone, either decreasing the amount of this hormone produced or preventing it from carrying out its normal functions(7). When this happens, the body retains more potassium, causing hyperkalemia. Here are just a few of those medications (7):

• Aldosterone blockers: These medications block the secretion of aldosterone. They include common blood pressure pills found in many medicine cabinets, such as lisinopril or losartan (8, 9). Their side effect can be hyperkalemia.
• Diuretics: Medications called diuretics (water pills) have potassium-sparing properties, such as spironolactone (10). 
• Beta-blockers: Drugs like atenolol, metoprolol, and propranolol used to treat high blood pressure and certain heart conditions can also cause high potassium levels. They do this by blocking a channel in blood cells that normally allows potassium to pass through. However, this way, potassium remains trapped in the bloodstream, leading to hyperkalemia. 

Many other medications can cause elevated potassium levels. These include some nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), immune-suppressing medications (e.g., tacrolimus), and antibiotics (e.g., Bactrim) (11, 12, 13). 

Blood pressure variations and hyperkalemia in adults 

High potassium levels do not cause high blood pressure in adults. However, hyperkalemia can indirectly lead to low blood pressure (hypotension) by impacting the heart (14).

When there’s excessive potassium in the bloodstream, it can interfere with the heart’s electrical activity (15). This can lead to dangerous heart rhythm abnormalities called arrhythmias. 

Here’s an analogy: arrhythmias are like your heart singing off-tune. You can still understand the song, but it sounds bad. Similarly, arrhythmias cause problems with your heart’s blood-pumping ability. Your heart continues to pump, but it doesn’t do it as effectively as it should. The dysfunction leads to reduced blood flow and low blood pressure. This is why the effects of hyperkalemia on the heart can be life-threatening.

Potassium levels are closely tied to blood pressure variations. This is because the kidneys serve multiple functions. In addition to handling potassium levels in the blood and urine, they also help regulate blood pressure. Therefore, conditions affecting the kidneys often cause problems with blood pressure and potassium levels.

For example, a condition called primary hyperaldosteronism causes excessive production of aldosterone. With too much aldosterone, the kidneys lose too much potassium, leading to hypokalemia. Since aldosterone also causes the kidneys to retain more water, and more water can elevate blood pressure, it follows that increased levels of aldosterone can also cause hypertension (16). 

Additionally, some people who take medications to lower their blood pressure can experience adverse effects. As previously discussed, some blood pressure pills block the production of aldosterone, leading to the combination of high potassium and low blood pressure. 

At this point, it should make sense how hyperkalemia is related to low blood pressure and low potassium levels are related to high blood pressure.

Studies exploring the relationship between dietary potassium intake and blood pressure have confirmed this (17). Namely, low-potassium diets (below 1.5 g/day) have been associated with an increase in blood pressure and even stroke. 

On the other hand, high-potassium diets have been shown to lower blood pressure in hypertensive patients with normal kidney function, but not in those with normal blood pressure (17). 

These results suggest that people with hypertension and normal or near-normal kidney function should be encouraged to eat plenty of fruits and vegetables to ensure enough potassium in their diet. Potassium supplements, only under a doctor’s supervision, may be needed for people who can’t get enough potassium from their diet alone. 

It’s not entirely clear how potassium intake influences blood pressure. One theory is that sodium plays a central role. Consuming a potassium-sufficient diet might lead to more sodium in the bloodstream. In fact, sodium and water are like travel buddies: they always move together. Consequently, more sodium in the bloodstream means more water there. This effect increases blood pressure. 

On the other hand, if you consume high amounts of potassium, more sodium leaves the body. Water leaves along with it, lowering blood pressure (18). 

Other side effects of high potassium in adults

Many people with hyperkalemia do not have any symptoms, particularly if their potassium levels are under 6 mEq/L. Symptoms are more likely to occur with levels above 6.5 mEq/L (1). When they first occur, symptoms can be vague, but they can progress to involve the muscles and heart.

General weakness and fatigue

General weakness and fatigue are the most common symptoms. According to the National Kidney Foundation, other signs of too much potassium can include nausea, vomiting, diarrhea, tingling, and numbness (19).

Muscle weakness, paralysis, and arrhythmias

The greatest dangers occur when potassium levels are 6.5 to 7 mEq/L (1). In these cases, severe muscle weakness or paralysis can develop. The electrical impulses of the heart can also be interrupted, leading to arrhythmias and an increased risk of sudden death (15). Since the heart is affected, people can also experience trouble breathing, chest pain, and heart palpitations.

Metabolic acidosis

This is the stage at which hyperkalemia can also interfere with the kidney’s ability to eliminate ammonia (20). When ammonia builds up in the bloodstream, it can cause it to become too acidic, leading to a condition called metabolic acidosis. Metabolic acidosis impacts every organ system, leading to confusion, dizziness, headache, difficulty breathing, and other symptoms. 

Pediatric hyperkalemia: challenges and treatments

The causes of hyperkalemia in adults can also apply to children. However, without testing the blood potassium levels, the vague nature of many symptoms of hyperkalemia can make it more challenging to recognize the condition early in children than in adults.

Like in adults, when potassium levels become very high in children (> 6.5 mEq/L), they have a high risk of developing muscle weakness or paralysis as well as heart rhythm problems. 

The treatment for pediatric hyperkalemia is similar to that for adults. Unlike adults, children typically require weight- and age-based dosing of medications to ensure the appropriate amounts are given. 

The priority in all cases is preventing abnormal heart rhythms, which are dangerous and can lead to sudden death. Several medications can be prescribed to help reduce blood potassium levels (21). These include:

• Sodium bicarbonate
• Insulin
• Albuterol
• Furosemide
• Patiromer
• Sodium polystyrene sulfonate

In severe cases, kidney dialysis may be needed. This is a procedure in which a machine filters potassium out of the blood in place of the kidneys.

When to see a doctor

Knowing when to see a doctor for hyperkalemia can be challenging. Normally, mild increases in potassium levels are not a cause for concern and can occur in mild chronic kidney disease. However, you should see your doctor if you develop symptoms that might indicate your levels are off, such as trouble breathing, muscle weakness, or chest pain. 

You should also see your doctor if your blood pressure readings are persistently low or high. Your doctor may run blood tests to ensure that potassium abnormalities do not lie at the root of your blood pressure variations.