If you are undergoing diagnosis for kidney disease, you may be symptomatic from the very beginning of your disease, or you may remain symptom free until you are nearly in renal failure. If you have advanced disease, you are likely to experience a very different set of symptoms than those whose disease is less advanced. However, there is a set of symptoms that are nearly universal. These first signs of kidney disease are often what initially brings patients to doctors.
Proteinuria
High urine protein is the red flag for renal disease and is usually the first thing doctors look to when beginning their diagnostic analysis. When kidneys function normally, the glomeruli (tiny tufts of capillaries which carry blood within the kidneys) prevent proteins from spilling into the urine. This is not true when kidneys are diseased.
If urine protein is very high, doctors refer to the patient as "being nephrotic." A nephrotic patient may have puffy eyes and swollen feet. Their urine will be very foamy. Often, they feel fatigued and experience a vague malaise. If urine protein is only mildly elevated, they may be entirely symptom-free.
Testing a urine sample for protein is called urinalysis. In his review article "Proteinuria" on emedicine.com, Ronald Kallen M.D. describes the different ways urinalysis can be performed. Some are very simple and involve nothing more than a dipstick inserted into a random urine sample provided by the patient. Other tests are more demanding and require that the patient collect all of the urine they void during a 24-period. Still others require that the patient provide a urine specimen from their first void of the day.
Curiously, while urine protein is a red flag for kidney disease, it does not indicate how severe that disease may be. Thus, a patient with very high urine protein may have almost normal renal function, and a patient with almost no urine protein may be near renal failure.
Hematuria
Patients who have blood in their urine are said to have hematuria. Urine may be tea-colored or scarlet red. This dramatic symptom is often very frightening to patients who look into the toilet bowl and see a bowlful of red urine. In a review article on emedicine.com, Sanjeev Gulati M.D. reports that children often present with the most dramatic hematuria.
Just like proteinuria, hematuria is measured by urinalysis. It can be tested by a dipstick test or by counting the number of red blood cells in a microscopic field. Dipstick tests are inaccurate because red blood cells can clump together on the paper and provide misleadingly large results. Counting cells in a microscopic field is more accurate.
High Cholesterol
Patients who have uncontrolled proteinuria usually have high cholesterol as well. When doctors measure cholesterol, they are actually measuring the set of proteins that transport cholesterol. If you are losing proteins due to proteinuria, your liver goes into overtime making more proteins to transport cholesterol. Thus, patients with proteinuria test high for cholesterol. Fortunately, once proteinuria is controlled, cholesterol levels come down as well. For example, in his "Annals of Internal Medicine" article, Taha Keilani, M.D. shows that when proteinuria is treated successfully with an ACE inhibitor, cholesterol values tend to normalize.
This symptom can be very distressing if you eat a heart-healthy diet and exercise because it seems to come out of nowhere. Fortunately, it can be easily controlled.
