A potassium blood test measures the amount of potassium in your blood. Potassium is a type of electrolyte. Electrolytes are electrically charged minerals in your body that help control muscle and nerve activity, maintain fluid levels, and perform other important functions. Your body needs potassium to help your heart and muscles work properly. Potassium levels that are too high or too low may indicate a medical problem.
Other names: potassium serum, serum potassium, serum electrolytes, K
A potassium blood test is often included in a series of routine blood tests called an electrolyte panel. The test may also be used to monitor or diagnose conditions related to abnormal potassium levels. These conditions include kidney disease, high blood pressure, and heart disease.
Your health care provider may order a potassium blood test as part of your regular checkup or to monitor an existing condition such as diabetes or kidney disease. You may also need this test if you have symptoms of having too much or too little potassium.
If your potassium levels are too high, your symptoms may include:
Irregular heart rhythms
Paralysis in the arms and legs
If your potassium levels are too low, your symptoms may include:
Irregular heart rhythms
A sodium blood test measures the amount of sodium in your blood. Sodium is a type of electrolyte. Electrolytes are electrically charged minerals that help maintain fluid levels and the balance of chemicals in your body called acids and bases. Sodium also helps your nerves and muscles work properly.
You get most of the sodium you need in your diet. Once your body takes in enough sodium, the kidneys get rid of the rest in your urine. If your sodium blood levels are too high or too low, it may mean that you have a problem with your kidneys, dehydration, or another medical condition.
Other names: Na test
A sodium blood test may be part of a test called an electrolyte panel. An electrolyte panel is a blood test that measures sodium, along with other electrolytes, including potassium, chloride, and bicarbonate.
Your health care provider may have ordered a sodium blood test as part of your regular checkup or if you have symptoms of too much sodium (hypernatremia) or too little sodium (hyponatremia) in your blood.
Symptoms of low sodium levels (hyponatremia) include:
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
You don’t need any special preparations for a sodium blood test or an electrolyte panel. If your health care provider has ordered more tests on your blood sample, you may need to fast (not eat or drink) for several hours before the test. Your health care provider will let you know if there are any special instructions to follow.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
If your results show higher than normal sodium levels, it may indicate:
A disorder of the adrenal glands
A kidney disorder
Diabetes insipidus, a rare form of diabetes that happens when the kidneys pass an unusually high volume of urine.
If your results show lower than normal sodium levels, it may indicate:
Addison disease, a condition in which your body’s adrenal glands don’t produce enough of certain types of hormones
Cirrhosis, a condition that causes scarring of the liver and can damage liver function