- Causes and types of proteinuria
- 1. Transient proteinuria
- 2. Orthostatic proteinuria
- 3. Persistent proteinuria
- Possible symptoms
- How the exam is done
- How to prepare for the exam
Proteinuria consists of an excess of protein found in the urine, which can be an indicator of several diseases, however, low levels of protein in the urine are considered normal. This is because protein molecules are large in size and therefore cannot pass through the glomeruli or kidney filters, and are not normally excreted in the urine.
The kidneys filter the blood, eliminating what does not matter and retaining what is important for the body, however, in some situations, the kidneys allow proteins to pass through their filters, causing an increase in the protein content in the urine.
Causes and types of proteinuria
Proteinuria can happen due to several situations and, depending on the cause and the time that the presence of proteins in the urine can be detected, proteinuria can be classified into:
1. Transient proteinuria
The situations that cause a temporary protein elevation in the urine are:
- Dehydration; Emotional stress; Exposure to extreme cold; Fever; Intense physical exercise.
These situations are not cause for concern, and are usually fleeting.
2. Orthostatic proteinuria
In orthostatic proteinuria, the amount of protein in the urine increases when standing, and is usually seen in children and young people who are tall and thin. Protein secretion in the urine occurs mainly during the day, when activity levels are high, so if urine is collected in the morning, it should not contain any proteins.
3. Persistent proteinuria
The diseases and conditions that cause persistently high levels of protein in the urine, can be the following:
- Amyloidosis, which consists of an abnormal accumulation of proteins in the organs; Prolonged use of some medications, such as non-steroidal anti-inflammatory drugs; Chronic kidney disease or polycystic kidney disease or kidney infection; Heart disease or infection of the inner lining of the heart; Lymphoma Hodgkin's disease and multiple myeloma; Glomerulonephritis, which consists of inflammation of the renal glomeruli; Diabetes, because it affects the ability of the kidneys to filter blood or reabsorb proteins in the blood; High pressure, which damages the arteries located in and around the kidneys, negatively affecting the function of these organs; IgA nephropathy, which consists of renal inflammation resulting from an accumulation of the immunoglobulin A antibody; sarcoidosis, which consists of the development and growth of inflammatory cell clusters in the organs; sickle cell anemia; lupus; malaria; rheumatoid arthritis.
High values of protein in the urine can also happen in pregnancy, and may be related to several factors, such as the increased work of the kidneys to filter excess fluids, excess stress, urinary tract infection, or in more severe cases, pre-eclampsia. See more about these symptoms of proteinuria in pregnancy.
Preeclampsia is a serious complication of pregnancy, which must be detected as soon as possible, in order to avoid health problems in the pregnant woman, which may be associated with other factors such as increased blood pressure, headache or swelling in the body. Learn more about pre-eclampsia.
Possible symptoms
Proteinuria can be the result of several situations, the symptoms not being specifically related to the presence of proteins in the urine, but to the causes.
However, if proteinuria is indicative of kidney disease, other symptoms may appear, such as nausea and vomiting, decreased urine production, swelling in the ankles and around the eyes, unpleasant taste in the mouth, fatigue, shortness of breath and appetite, pallor, dryness and generalized itching of the skin. In addition, the urine may also be foamy and cause pain and a burning sensation when urinating. Understand what kidney failure is, symptoms and how treatment is done.
Treatment depends a lot on the cause of proteinuria, so one must go to the medium in order to make the correct diagnosis, and determine what is causing the excess protein in the urine.
How the exam is done
Proteins can be easily detected in the urine with the help of a urine test with reagent tape, in which the urine sample is collected and a strip of paper with chemical reagents is dipped, and if the urine sample contains too much protein, the strip changes color. Know what the urine test is for and how to do it.
If urine is found to have large amounts of protein, a 24-hour urine test can also be performed to measure protein and creatinine clearance, which helps to assess and control kidney function, thereby helping to detect possible diseases. Learn all about the 24-hour urine test.
Urine samples are collected in one or more containers over a period of 24 hours and kept in a cool place. Then, they are sent to a laboratory to be analyzed. This test does not show what types of protein are present in the urine, so to determine the types of protein present, the doctor may advise you to perform other tests such as an electrophoresis of the proteins present in the urine.
How to prepare for the exam
Before performing the exam, you should speak to the doctor in order to prepare correctly, so that the result is not wrong. Therefore, it is necessary to stop taking some medications or supplements that may interfere with the test results.
Other factors may interfere with the test, such as dehydration or not drinking enough water, having undergone a radiological contrast test in which some type of dye has been used, having been subjected to a situation of extreme emotional stress, extreme physical exercise, if you have a urinary tract infection, or if your urine is mixed with vaginal secretions, blood or semen.
If the urine test is done on women, it is very important to wait 5 to 10 days after the end of the menstrual cycle before taking the test, to avoid contaminating the urine with traces of blood from the period.
