What do we want to explain a urine analysis?
“Fortunately, it is a procedure of the past, when doctors looked for macroscopic elements (blood, pus, solid remains), more or less intense colors and other markers such as the smell of ammonia or the sweet taste”, says the head of the Service of Urology at the Fundació Jiménez Díaz University Hospital in Madrid.
Since the 19th century, it has been known that the analysis of urine will be the most important element of the clinical diagnosis to find out the constitution of the blood and the body’s chemical processes. But it will not be until the development of various chemical and microscopic techniques, especially when it is given the scientific character that we admire today.
A urinalysis is part of the patient’s medical history along with the history, physical examination, blood tests, imaging and genetic tests, if applicable, or the result of a rectal examination in the event that it is a urological consultation masculine or feminine”, emphasizes Dra. González Enguita.
Why is urinalysis so important?
Urine is a yellowish liquid that is secreted by the kidneys as a result of the purification and filtering of the blood, the final conclusion of the cellular metabolism and therefore of the functioning of all the organs of our anatomy.
The urine, which comes out of the two kidneys through the ureters, accumulates or stores in the bladder and is expelled outside the human body through the urethra during the dynamic process of urination.
The bladder demonstrates a capacity of about half a liter (500 ml) in the case of women and 700 milliliters in the case of men. People produce between 1.5 and 1.7 liters of urine each day.
“Therefore, it is always relevant that a person who reflects some kind of symptom, a disease or who suffers from a disease conveys to the doctor his impressions about the appearance of his own urine: whether it is clear or cloudy, the color and the “smell, or if it contains elements such as blood or solid remains”.
Dr. Carmen González Enguita
The ideal context for a good urine analysis
A urinalysis is a very common study that provides a large amount of clinical information, is done quickly and has a low economic cost for the National Health System based on the very high medical benefit.
So much so that it is essential to make one correct collection of our urineas indicated by the specialist depending on the objective to be studied, to help the best and fastest diagnosis and treatment of a pathology.
“A poorly collected sample, in an inappropriate container, can not only become useless for the indicated research, but can lead to errors in the results and, as a consequence, an incorrect interpretation of the data”, he warns.
The way to collect the sample, the time, the type of container, the amount (sometimes urine/24h is required), the storage temperature, the storage and custody until it arrives at the laboratory and the time that passes until it is analyzed they will be key to a perfect medical examination.
In addition, there will be certain processes in the state of health or disease that will require specific studies that are not determined in a routine or conventional analysis of a urine sample.
In these cases, it is the doctor who expressly requests from the laboratory staff what he wishes to be investigated: what is of special value for the study of the diagnosis or monitoring of the disease.
The focus of these more common specific requests would be placed on pregnancy, urine cultures (microbiology study)urine cytology (tumor cellularity)detection of illicit drugs, bone, lithiasic and endocrine metabolism (hormones)specific oncological markers, removal of minerals and drugs (dose control in treatments).
It will also be necessary to consider the result of the analysis based on other variables that may alter certain set parameters, such as the physical exercise performed by the patient, what he has eaten previously, alcohol consumption, fever, etc., without this supposes the existence of a pathology.
The intrinsic value of urinalysis
“By itself, a urinalysis does not provide a definitive diagnosis. It will help the doctor, together with the rest of the data from the clinical history, to follow up the disease, if necessary, or determine the steps to follow with the results obtained”, says the Dr. González Enguita.
“Depending on the reason why the doctor recommends this study, and in the face of unusual results, it may be necessary to evaluate the results of the urinalysis along with other studies,” he adds.
“On the other hand, analysis results classified as good, standard, do not represent a guarantee of an adequate state of health. It could be that it was too early to detect the disease or that the urine analyzed was too diluted.hypotonic-“, completes the urologist.
A urine analysis is requested for different reasons: to assess a person’s general health, to diagnose a disease and to monitor the evolution of a pathology.
The routine medical examination checks the usual and conventional urinary parameters to find out if the patient is healthy or suffers from some incipient pathology:
- Preoperative before a surgery.
- Suspected detection of various disorders, such as diabetes, kidney or liver disease.
- Pregnancy diagnosis.
- Other situations, such as during a hospital admission through the Emergency Department or after a consultation with the specialist.
When we go to a medical consultation because we notice that something is not working well in our body, it is more than likely that, among other tests to be performed, the doctor, before issuing the diagnosis, will request a urine analysis and another of blood.
A urinalysis can help diagnose the cause of signs and symptoms that may be expressing an illness. The most common symptoms:
- Abdominal pain
- Back pain.
- Frequent or painful urination.
- Blood in the urine or other urinary problems.
If the patient has been diagnosed with a condition, such as kidney disease or urinary tract infection, the urologist may recommend a periodic urinalysis, on a regular basis, in order to monitor the evolution of the disease and the outcome of the treatment applied.
Master collection of urine for analysis in the laboratory
It will be the doctor or nurse who must instruct the patient in good practice for collecting the urine sample. It is convenient, unless otherwise medically indicated, that it be the first urine in the morning, when it is more concentrated.
“In any case, they also have to explain to us if the urine is what ‘self-collection’ it will be at the beginning of urination, in the middle or at the end of the urinary stream”, explains Dra. Carmen González Enguita.
“Also, it is common for us to be asked about the need to come fasting, or not, on the day of collection…. Patients should ask. It is better to avoid doubts and confusion, especially when the pathological situation requires it”, he underlines.
How to properly collect urineespecially if it is the first time, to avoid diagnostic errors and the data not to be useless:
- Wash your hands thoroughly before handling the sample collection container.
- Then wash the area where you urinate. Women should part the labia at the vulva and wipe forward. Men should clean their glans and urethral meatus (outlet).
- Urination will be in the toilet.
- Place the container (jar, tube, flask or jar) in the urine stream.
- Urinate at least 30 to 60 milliliters into the container.
- Finish peeing in the toilet.
- Close the container according to the instructions for use.
- Wash your hands again.
- Leave the sample in the laboratory as soon as possible.
- Resume normal activities immediately.
The sample must be collected at home or at the hospital, close to the laboratory. If it is collected at home, it should conveniently be deposited in the laboratory always before 60 minutes. If this is not possible, it must be stored at a low temperature (in a refrigerator or similar).
Likewise, it is common for the specialist to request a recent urine analysis, so the urine will need to be collected at the same hospital center where the analysis is requested in order to study it immediately.
At the same time, it will be mandatory, or not, a matter for the doctor to decide, to suspend certain medicines in the hours before the collection of the sample, throughout the previous day or during the previous days necessary so that the results are not masked.
“Before revealing the secrets that urine keeps in its deepest intimacy (which we will see in the second chapter of this series of two video blogs focusing on urinalysis, which will be published next Friday, September 16) I must emphasize that our urine gathers a huge amount of information about ourselves and what happens to us”
The doctor and surgeon concludes Carmen González Enguita.