Principles of Urinalysis Flashcards
Describe the colour of urine
Ranges from pale straw to amber colour depending on concentration
What determines urine colour?
urochrome - a by-product of haemoglobin breakdown and concentration/hydration
What is the normal clarity of urine?
Usually transparent
How would you describe the smell of fresh urine?
Ideally should not be offensive
What is the normal pH of urine?
Ranges from 4.5 - 8
acidic around pH 6
What is the specific gravity of urine?
1.002 - 1.035
What does a higher gravity of urine indicate?
1.035 is more concentrated as occurs in dehydration
What does a lower gravity of urine indicate?
A lower reading (1.002) indicates more dilute urine e.g. due to higher fluid intake
What percentage does water constitute to urine?
96%
What dissolved substances are in urine?
- urea and other substances
- uric acid
- creatinine
- ammonia
Give examples of ‘urea and other substances’ found in urine?
uric acid, sodium, potassium, creatinine, sulphates, oxalates, chlorides
What is uric acid found in urine?
breakdown of nucleic acid urea - product of protein breakdown in liver
What is creatinine found in urine?
results from metabolism in muscles
What is ammonia found in urine?
by-product of amino acid breakdown
When would urinalysis be carried out during pregnancy?
- antenatal booking & appointments
- monitor during labour
- admission to hospital
- specific medical disorder apparent
- clinical symptoms e.g. dysuria
- altered micturition
What effects the colour of urine?
- hydration
- haematuria (blood in urine)
- diet (red foods - beetroot)
- medications
What is the significance of cloudy urine?
- Cloudy if left to stand for several minutes due to precipitation of solutes.
- Proteinuria
- Bacteriuria
What can affect the odour of urine?
- high concentration
- stagnant urine has an ammonia smell
- ketones = sweet odour
- infection = fishy, offensive odour
- foods - fish, curry etc
What can cause protein to be present in the urine?
contamination, infection or underlying disease
Why might blood be present in the urine?
infection, trauma, disease or vaginal contamination
Why might glucose be present in the urine?
- glycosuria can be result of glucose threshold being lowered during pregnancy
- diabetes
What are ketones? Why might ketones be present in the urine?
- Product of fat metabolism
- Due to fasting, vomiting, diabetes, in labour if energy stores reduced
Why might nitrites be present in the urine?
Nitrates from diet are converted to nitrites in the presence of bacteria therefore if in urine indicative of urinary tract infection
What does high levels of urobilinogen mean in the urine?
May indicate liver abnormalities or excessive destruction of red blood cells as in haemolytic anaemia
Why might leucocytes (white blood cells) be present in urine?
Inflammation or infection along urinary tract often in the bladder or kidney
