How is frequent urination diagnosed?

Your doctor is likely to perform a physical examination followed by a series of questions regarding any medications you are taking and your medical history.

Doctors typically ask some of the below questions:

• How often are you urinating during the day and how many times do you have to wake up to urinate during the night?
• What colour is your urine? Have you noticed any colour changes in your urine?
• Are you suffering from any discomfort, pain or burning when you urinate?
• Have you recently made any dietary changes?
• Are you experiencing any other symptoms such as fever, weight loss, back pain or increased thirst?

Once you have answered the above questions, and a physical examination has been conducted, your doctor may perform or order some of the below tests:

• Urinalysis – This refers to a set of screening tests which involve a microscopic exam of your urine to detect a wide range of conditions such as kidney disease, diabetes and UTI (urinary tract infection). Urinalysis is cost effective and performed in most doctor’s rooms, all you have to do is provide a urine sample.
  The results can be obtained within a number of minutes of the sample collection. A urine dipstick, which is a narrow plastic strip containing a number of different coloured squares attached to it is used to determine the results. Each one of these squares is representative of a component of the test. The entire strip will be dipped into your urine sample and each colour change on the strip will be noted.
  
  A urinalysis will involve checking the concentration, appearance and content of your urine. If the results are abnormal then this may be as a result of a certain condition.
  
  A urinalysis is often combined with other tests such as a urine culture test. This test is usually conducted at the same time as a urinalysis or as a follow-up to abnormal test results. A urine culture is a test that is used to detect bacteria or other germs in the urine that may be causing a urinary tract infection (UTI). A urine culture is usually conducted in addition to a urinalysis as urinalysis cannot detect the type of bacteria causing an infection, only whether there are any issues in the body (i.e. the biochemical functions of the body). Once an issue is identified, further testing is necessary to ascertain what is causing it.

• Ultrasonography – This diagnostic imaging test is a non-invasive procedure that uses high-frequency sound waves to produce images of the internal organs. This test is conducted in order for your doctor to visualise your bladder and kidneys and detect whether or not there are any structural abnormalities or tumours present that may be contributing to frequent urination.
• Cystometry (cystometric study) – This test is more invasive and measures bladder pressure to determine the functioning of the bladder in order to detect any abnormalities within the nerves or muscles of the bladder that could be causing issues with how well your bladder holds and releases urine. If you suffer from urinary incontinence, find it difficult to urinate, or if your bladder function is affected a result of a neurological condition, then your doctor may suggest that he or she performs this test.
  
  My Med Memo - You will not have this test conducted if you currently have an active UTI as this could spread the infection to your bladder.
  
  In order for cystometry to be conducted, a local anaesthetic will be administered, after which, a catheter will then be inserted in the urethra and then into the bladder. This process often causes a slight burning sensation. The catheter is then used to measure the amount of urine in the bladder at the time. Thereafter, a second catheter will be inserted into the rectum. A tube is attached to this catheter, known as a cystometer to measure the pressure in your bladder. You will then be asked to report on feelings of pressure, pain, fullness and urgency to urinate as your doctor fills your bladder with a water and saline solution. Once the bladder is completely full, you will be required to urinate, and your doctor will record the pressure of your stream of urine when doing so through the use of a urine flow test. The flow rate of urine is measured using a specialised funnel that will determine the amount of urine and flow rate over the duration of time it takes to urinate.
• Cystoscopy – This invasive test involves your doctor using a thin tube known as a cystoscope with a light at the end of it in order to gain a look inside the urethra and bladder. Your doctor will insert the tube through your urethra and then into the bladder. Images will then be captured on a screen for examination.
  
  This procedure is done under anaesthesia and is usually performed in a hospital setting.
• Neurological tests – Certain diagnostic procedures and tests such as imaging, EEG (electroencephalogram), EMG (electromyography) or urodynamics help your doctor to rule out or confirm if you have a neurological disorder.

What colour should my urine be?

Your urine consists of waste products and water that your kidneys have processed and filtered out of the blood. If all the biochemical processes in your body are healthy and functioning correctly, then your urine will be a pale-yellow colour. The yellow colour of urine is due to a pigment in your body known as urochrome, this is one of the substances that is produced when heamoglobin (i.e. a protein found in red blood cells that binds to oxygen to be transported around the body) is broken down in your body. The intensity of the colour of your urine depends on the concentration of this pigment.

The shades of yellow of urine may range from light to dark, however, if there is no colour to your urine, then this may be because you are drinking larger quantities of water than your body needs, or you are taking a diuretic, which will help to rid your body of fluid. If your urine is a very dark yellow, then this may be a sign of dehydration and it is advised that you drink more water to rehydrate. Changes in the colour of your urine can often be harmless and may be dependent on the food or drinks you have ingested or medications you have taken.

Unusual colours of urine include:

• Red – This colour of your urine may vary between pink and a very intense red, if you notice that your urine is red then your doctor may perform a simple test to determine if this red colour is as a result of haematuria (this is the medical term for the presence of blood in urine). The red colour may also be caused by myoglobin being present, this is a protein that binds to oxygen in your muscle cells and is similar to the haemoglobin found in your red blood cells.
  
  Red urine may also be the result of issues that affect your urinary system (i.e. the ureters, bladder, kidneys and urethra) that allow for blood to enter the urine. There is a long list of conditions such as bladder infections, kidney stones and even bladder cancer, or, in men, an enlarged prostate which may cause red urine.
  
  In some cases, strenuous exercise can also result in blood in the urine, the exact reason as to why this occurs is not yet known, but it is thought that it may be due the movement of the bladder during exercise or a result of the breakdown of red blood cells during aerobic exercise⁵.
  
  Haematuria may also be caused by inherited disorders like sickle-cell anaemia or thalassemia (a blood disorder that leads to decreased levels of oxygen-carrying proteins) as these conditions affect haemoglobin and red blood cells.
  
  Bear in mind, there is also a harmless cause of red-coloured urine known as beeturia, this occurs after you have eaten beets (beetroot). For this discolouration to take place, the conditions within your intestines and stomach will need to be just right for the pigment, known as betalain, to not lose its colour. If you suffer from iron deficiency and eat beets, as well as foods containing a substance known as oxalate, the occurrence of beeturia is more likely.  

• Black or brown – Urine may even appear brown or black, in cases such as these, the cause of urine discolouration is likely due to the same reasons as those pertaining to red urine. However, if your urine is truly brown this may be due to the presence of bilirubin, a biproduct of haemoglobin which can accumulate in the blood as a result of liver disorders such as cirrhosis or hepatitis, gallstones, a tumour or something blocking the bile duct. Should excess bilirubin reach the urine, this may result in a brownish colour. Bilirubin may also taint the urine when too many red blood cells are broken down simultaneously, creating a surplus of bilirubin.
  
  If you have a severe type of skin cancer known as melanoma, then, in rare cases, the pigment responsible for darkening skin (known as melanin) may enter your body’s blood stream with some of this pigment eventually reaching your urine.
  
  Certain foods such as rhubarb or fava beans can also turn urine brown.
• Orange – There are several different medications that may turn your urine orange, these include isoniazid (this is a popular treatment for tuberculosis (TB)), as well as another TB drug known as rifampin. Other drugs which include high doses of vitamin B (riboflavin) and a medication used to treat urinary tract infections known as phenazopyridine (Pyridium) which eases the pain experienced when urinating can also turn urine orange. In some cases, large amounts of carrot juice may also give your urine an orange hue.
• Milky-white – If you have a urinary tract infection, this may cause your urine to turn a milky-white colour due to the immune response to the infection that leads to white blood cells (these form a part of your body’s natural defence system) entering the urine.
  
  In some cases, whitish urine may be a result of uric acid crystals which come from eating foods that are purine-rich, these include herring, red meat and anchovies. Phosphate crystals can also turn urine white and may be present therein as a result of the body containing excess amounts of parathyroid hormone which impacts the kidneys ability to eliminate phosphate, this is known as the phosphaturic effect. Phosphate crystals are needed by the body to build and repair your teeth, bones and to aid in muscle contraction and nerve functioning.
• Blue – Your urine may appear blue in colour as a result of a substance called methylene blue. This dye is used in a number of diagnostic tests and medications due to its antimicrobial properties, it is also used for the treatment of some rare health conditions.
  
  Certain inherited disorders such as blue diaper syndrome (a rare metabolic disorder that affects children) and Hartnup disease (a condition that affects the body’s ability to absorb amino acids from food) can also lead to blue urine.
• Green – Should blue pigment taint your urine, then the colour may appear as green when the blue is mixed with the yellow urochrome of your urine. While having green urine is not a common occurrence, the colour discolouration may also be due to the administration of an anaesthetic known as Propofol, a stomach acid medication called cimetidine (Tagamet), as well as an antidepressant known as Elavil, in cases such as these, green urine is a harmless side effect.
  
  Occasionally, eating asparagus can add a greenish hue to your urine, this is nothing to worry about.
  
  In some cases, green urine may be a sign of a UTI (urinary tract infection) or a bacterial infection that has entered the blood stream, this is known as bacteraemia. Should urine discolouration persist, then it is advised that you make an appointment to see your doctor.
• Purple – If your urine is purple, then this is known as purple urine bag syndrome (PUBS) and is the only urine colour with a specific syndrome named after it⁵. This rare condition arises when bacteria accumulates in a urinary catheter (and/or the collection bag) and the condition often co-exists with a urinary tract infection. When bacteria colonise as a result of a catheter, a substance known as indirubin is produced as a result, this is red and indigo (creating a purple hue when mixed together).
  

 

^References: 

^{5. Harvard Medical School. 2012. Red, brown, green: Urine colors and what they might mean. Available: https://www.health.harvard.edu/newsletter_article/red-brown-green-urine-colors-and-what-they-might-mean [Accessed 18.01.2017]}