This lesson will discuss four major electrolytes that are found in your blood. But we'll be discussing the significance of finding more or less than normal amounts of them in your urine.
The Many Locations of Electrolytes
Let's play a game of 'Where's Waldo?,' biochemistry style. I'm going to name off a substance and then see if you can figure out where it's found besides my examples.
- Calcium: in milk
- Sodium and chloride: in table salt
- Potassium: in meat and dark greens
Some of you may be shouting at the screen and telling me they're also found in our blood and in our cells. Yes, yes, they are. But they're also found in our urine. And sometimes that's a sign of a serious disease you should be concerned about.
Urine Calcium and Phosphate
Calcium and phosphate are substances found in milk, in our cells, in our blood, in our bones, and oh so many other places. They're very important little electrolytes involved in many things, ranging from nerve signal conduction to muscle contraction. Without calcium and phosphorus, Waldo would have very little ability to move and talk and would have very weak bones.
If the levels of calcium or phosphorus excretion are found to be elevated in urine, then the first thing I want you to think about is hyperparathyroidism, a disease where excess parathyroid hormone is secreted.
On the flip side, both calcium and phosphate may be lower than normal in urine in cases of the exact opposite of hyperparathyroidism, hypoparathyroidism, which is an underactive parathyroid gland.
Other causes for increased urine calcium and phosphate excretion include hypervitaminosis D, or an excess of vitamin D, and any significant disease that causes the destruction of bone, such as certain types of cancer.
Logically, decreases in dietary intake of either calcium or phosphorus will lead to their respective decreases in the urine as it similarly occurs in hypoparathyroidism.
Urine Sodium and Chloride
Two other electrolytes, those that love to couple together to make table salt, can also be increased or decreased simultaneously due to many conditions. Like phosphorus and calcium they may sometimes, but not always, increase or decrease together. They are sodium and chloride. Without these two substances, Waldo would have a tough time digesting his food and maintaining proper blood pressure.
Low levels of chloride in the urine are sometimes a result of vomiting. There is a lot of chloride in your stomach, and if you vomit too much for too long, then you might deplete your body of it.
Furthermore, both sodium and chloride may decrease in the urine if there's an excess of steroid hormones called glucocorticoids in something known as Cushing's syndrome. On the flip side, if there is too little of these steroids, in a disease called Addison's disease, then their levels will increase in the urine.
Last for this lesson, but certainly not least, our potassium can be measured in the urine as well. Waldo has a lot of potassium in his cells. However, too much potassium outside of his cells, in his blood, can actually kill him!
But in our case, elevated levels of potassium in the urine may be as a result of many different conditions that affect the kidneys in addition to uncontrolled diabetes. Low levels of potassium in the urine may be a consequence of Addison's disease, the same thing that caused an increase in sodium levels in the urine.
As a quick review, let's go over why calcium and phosphate may increase or decrease in the urine. Increases are sometimes attributed to hyperparathyroidism, a disease where excess parathyroid hormone is secreted, or hypervitaminosis D, which is an excess of vitamin D. On the other hand, their decreases in the urine can be a result of hypoparathyroidism, which is an underactive parathyroid gland.
Sodium and chloride can increase together in the urine in cases of Addison's disease but will decrease in Cushing's syndrome.
In opposition to sodium and chloride, potassium levels in the urine will actually decrease in Addison's disease.
When you have finished this lesson, you should be able to explain the possible reasons for changes in calcium, phosphate, sodium, chloride, and potassium levels in urine.