Low potassium levels can cause symptoms like fatigue and
frequent urination. Increasing your intake of potassium-rich
foods, like fruits, vegetables, beans, and nuts, may help.
Potassium is an essential mineral that plays many roles in the
body. It helps regulate muscle contractions, maintain healthy
nerve function, and regulate fluid balance.
Despite its importance, it’s estimated that most adults don’t
meet their daily needs. This is likely due to the Western-style
diet, which favors processed foods over whole plant foods that
are high in potassium — such as fruits, vegetables, beans, and
nuts.
Low potassium, or potassium deficiency, is when your blood
potassium level is below 3.5
mmol per liter. In the medical
community, it’s known as hypokalemia.
Keep reading to learn more about potassium deficiency, including
its causes and symptoms.
Symptoms of potassium deficiency
Here are 7 signs and symptoms of potassium deficiency.
Weakness and fatigue
Weakness and fatigue are common
signs of potassium
deficiency for a few reasons:
when blood potassium levels are low, your muscles produce
weaker contractions
a deficiency may affect how your body uses nutrients in a
way that can result in fatigue
For example, some evidence shows that a deficiency could
impair insulin production.
This can result in high blood sugar levels and less available
glucose, which functions as energy for your cells.
Muscle weakness and cramps
Muscle cramps are sudden, uncontrolled contractions of the
muscles. They can occur when blood potassium levels are low and
can be painful.
Within skeletal muscle, potassium helps relay signals from your
brain to stimulate contractions. It also helps end these
contractions by leaving the muscle cells. When blood potassium
levels are low, your brain cannot relay these signals as
effectively.
This results in more prolonged contractions and is thought to
contribute to muscle cramps. Cramps are unlikely to occur with
mild or moderate hypokalemia, but they may happen with severe
hypokalemia of less than 2.5
mmol/LTrusted
Source of potassium.
Digestive problems
While digestive problems have many causes, they may occur with
severe hypokalemia.
Potassium helps relay signals from your brain to muscles located
in the digestive system known as smooth muscle. These signals
stimulate contractions that help your digestive system churn and
propel food, so it can be digested.
With low potassium levels, contractions in the digestive system
may become weaker and slow the movement of food. This could
cause digestive problems like bloating and constipation.
Abnormal heartbeat
Potassium also plays a vital role in maintaining healthy heart
muscle contractions.
This is because the flow of potassium in and out of heart cells
helps regulate your heartbeat. Low blood potassium levels can
alter this flow,
resulting in abnormal heart rhythms known as heart
arrhythmia.
Heart arrhythmias can also be a sign of a serious heart
condition. If you notice any abnormal changes to your heart
rate, seek immediate medical attention.
Tingling and numbness
Though more common in people with high potassium, or
hyperkalemia, those with potassium deficiency may also
experience persistent
tingles and numbness.
This is known as paresthesia and
usually occurs in the hands, arms, legs, and feet.
Potassium is important for healthy nerve function. Low blood
levels can weaken nerve signals and result in tingling and
numbness.
While occasionally experiencing these symptoms is harmless —
like if your foot falls asleep from lack of movement or sitting
in an awkward position — persistent tingles and numbness may be
a sign of an underlying condition.
If you experience this, it’s can be helpful to speak with
doctor.
Polyuria (frequent urination)
Polyuria is a condition where you pee more than usual.
The kidneys are responsible for balancing your body’s fluid and
electrolyte levels and removing any waste through the urine.
Low potassium levels may
impair your kidneys’
ability to concentrate urine and balance the blood’s electrolyte
levels, leading to increased urination. You may also notice
increased thirst, known as polydipsia.
Excessive urination may lead to lower levels of potassium.
Therefore, it’s important to speak with a doctor if you notice a
sudden change in how often you urinate.
High blood pressure
Having the perfect balance of electrolytes is
important for maintaining healthy blood pressure.
You may be aware that consuming too much sodium can increase
blood pressure in some people. Yet, few people know that too
little potassium in the diet can have the same effect.
Potassium helps your kidneys get rid of excess sodium via urine.
If there isn’t enough potassium in the blood, the kidneys
reabsorb sodium back into the bloodstream, potentially leading
toTrusted
Source high blood pressure
over time.
This most often occurs with a low dietary intake of potassium —
and specifically with hypokalemia.
Therefore, getting enough potassium in your diet may help
maintain healthy blood pressure in some individuals.
Causes of potassium deficiency
Most often, potassium levels get low when you lose it
through your pee after you take medications such as
diuretics (water pills) for heart disease or high blood
pressure.
While it’s generally rare to develop potassium deficiency, certain
illnesses or other factors can cause it,
including:
chronic diarrhea, which can be caused by the overuse of
diuretics or laxatives, irritable bowel disease, or infections
certain medications, such as diuretic drugs
eating disorders, such as anorexia nervosa, purging, or laxative
abuse
under-eating or malnutrition
Cushing’s syndrome
hyperaldosteronism, where there is excess aldosterone, a steroid
hormone, in the blood
kidney failure
kidney disorders, such as Bartter syndrome, Gitelman syndrome,
and Fanconi syndrome.
hypomagnesemia (low magnesium levels)
excessive sweating
If you’re taking certain medications for kidney disease, such as diuretics,
and you suspect your potassium is low, consider speaking with a
healthcare professional. They can review your blood tests and adjust
your medications or diet as needed.
If you’ve experienced chronic fluid loss or have misused any
medications, seek immediate medical attention.
Hypokalemia Diagnosis
To determine if you have hypokalemia, your doctor will do a
potassium blood test to measure the levels of potassium in
your blood. They may do this as part of a comprehensive
metabolic panel, a series of blood tests that look at how
well your kidneys are working and whether levels of minerals
called electrolytes are
in balance.
Doctors measure potassium by millimoles per liter (mmol/L).
Normal potassium levels
Potassium levels ranging from 3.5 mmol/L to 5.5 mmol/L are
considered normal for adults.
Low potassium levels
If the potassium in your blood serum is below 3.5 mmol/L,
you have hypokalemia. If your level is in the range of
3.0-3.4 mmol/L, you have mild hypokalemia, and if your level
is lower than 3 mmol/L, you have moderate hypokalemia. If
your potassium level is below 2.5 mmol/L, you have severe
hypokalemia.
To find out the cause of your low blood potassium, your
doctor will ask you about your health history. For instance,
they’ll want to know if you’ve had any illnesses that
involved vomiting or diarrhea. They’ll also ask about any
conditions you might have and any medications you take.
You may take a urine test so your doctor can find out if
you’re losing potassium when you pee.
As low potassium sometimes can affect your blood pressure,
your doctor will check that, too. They also may want to do
an electrocardiogram (EKG)
if they think you may have arrhythmia. This is one of the
more serious side effects and might change the way your
doctor chooses to treat the problem.
How to treat hypokalemia
In most cases, hypokalemia will need to be treated by a healthcare
professional.
Mild to moderate hypokalemia is typically treated with oral
potassium supplements. In some cases, a healthcare professional may
also need to adjust any other medications or treat underlying
causes, like diarrhea, vomiting, or eating disorders.
A potassium-rich diet is usually not enough to treat hypokalemia,
since most potassium in food is paired with phosphate, not potassium
chloride. Hypokalemia often also involves a chloride deficiency, so
it’s best to treat both deficiencies with potassium chloride
supplements.
Usually, 60–80
mmolTrusted
Source of supplements per day
for a few days to weeks is sufficient for treating mild to moderate
hypokalemia. That said, it’s important to always follow the
recommendations of a healthcare professional.
In severe hypokalemia cases, intravenous (IV) treatment may be
recommended. This should be strictly monitored by a healthcare
professional due to the high risk of rebound hyperkalemia, or high
potassium, which can be fatal.
Should you take potassium supplements?
Self-treatment of hypokalemia with over-the-counter (OTC) potassium
supplements is not recommended.
This is because taking too much potassium can cause excess amounts
of the mineral to build up in the blood, resulting
in complications like heart arrhythmia.
Unless they’re prescribed by a healthcare professional, and you’re
being closely monitored, you should avoid taking potassium
supplements.
You may need to get potassium by IV in the hospital in
some cases, such as:
When your potassium level is dangerously low (you
have severe hypokalemia)
If taking supplements by
mouth doesn't raise your potassium levels
If your low potassium levels cause abnormal heart
rhythms
Sources of potassium
If you have diarrhea or are vomiting, drink plenty
of fluids. If you're losing lots of fluid through
diarrhea and vomiting for more than 1-2 days, talk
to your doctor. They may want to test your levels of
potassium and other electrolytes.
Avoid drinking too much alcohol (8-15 drinks per
week or 4-5 drinks over 2-3 hours, depending on your
size and gender).
A diet high in potassium may help prevent
hypokalemia. In the U.S., the recommended daily
intake of potassium for most adults is between 2,600
and 3,400 milligrams.
Here’s a table of foods that are excellent sources of potassium:
Food
Serving size
Potassium content
Daily Value (DV) %
Dried apricots
1 cup
(130 grams)
1,511 mg
32%
Cooked lentils
1 cup
(198 grams)
731 mg
16%
Cooked acorn squash
1 cup
(205 grams)
896 mg
19%
Cooked potato
1 medium
(136 grams)
515 mg
11%
Canned kidney beans
1 cup
(180 grams)
779 mg
17%
Orange juice
1 cup
(249 mL)
443 mg
9%
Banana
1 medium
(118 grams)
422 mg
9%
Milk (1% fat)
1 cup
(244 mL)
388 mg
8%
Tomato
1 medium
(100 grams)
260 mg
6%
Brewed coffee
1 cup
(240 mL)
118 mg
3%
Dried Prunes
1/2 Cup
635 mg
14%
While increasing your potassium intake won’t likely raise your
low potassium levels, eating a potassium-rich diet is still
beneficial to your health.
Hypokalemia FAQs
What blocks potassium absorption?
Aside from diuretics and laxatives, some other medicines,
such as steroids and some antacids, may either block your
ability to absorb potassium or cause you to lose more when
you pee and poop. Too much sodium in your diet may cause you
to lose more potassium when you pee. Eating a lot of
licorice can cause hypokalemia, as well.
What are the risk factors for hypokalemia?
People with some medical conditions, such as inflammatory
bowel disease, don't absorb potassium as well as others.
Also, people with inflammatory bowel disease usually have
chronic diarrhea, which can further decrease potassium
levels. Those with pica, a condition where people eat
non-food items, have a higher risk of hypokalemia,
especially if they eat clay. Clay binds to potassium in your
digestive tract, which causes you to lose potassium through
your poop.
The bottom line
Few people meet the daily recommended potassium
intake, which is 3,400 mg for males and 2,600 mg for
females.
Nevertheless, hypokalemia is rarely caused by dietary
deficiency alone. It can be caused by a number of
factors, including fluid loss, malnutrition, shock,
using certain medications, and medical conditions like
kidney failure.
Common signs and symptoms of potassium deficiency
include:
weakness and fatigue
muscle cramps
stiffness
tingles and numbness
If you think you may be deficient, it’s important to speak with a
healthcare professional. Potassium deficiency can have serious
health consequences.
If you notice any sudden changes in your breathing or heartbeat,
seek immediate medical attention.
Just one thing
Try this today: Aim to have 2–3 potassium-rich foods each day.
For example, a banana for breakfast, 1/2 cup (130 grams) of kidney
beans at lunch, and white potatoes on your dinner plate.
Takeaways
You have hypokalemia when you have low potassium levels in your blood.
This could be for a number of reasons, but often it's because you lose
potassium through your pee after you take medications such as a
diuretic. Unless your potassium
levels are dangerously low, you usually treat low potassium with
potassium supplements. To help avoid hypokalemia, drink plenty of fluids
when you take a medicine that makes you pee a lot or if you have an
illness that makes you vomit or have diarrhea. If you think you have low
blood potassium, talk to your doctor.