Urine Color Chart: Healthy and Abnormal

Color, turbidity (transparency), smell (odor), pH (acidity, alkalinity), and density are physical characteristics of the urine. Many of these characteristics are noticeable and distinguishable by sight alone, but others necessitate laboratory testing.

• Color
  • Typically, yellow to amber but varies depending on recent diet and urine concentration.
  • Drinking more water generally reduces the concentration of urine, causing it to be lighter. 
  • Dehydration can be indicated by dark urine.
  • Red urine indicates the presence of red blood cells in the urine, which is a sign of kidney damage and disease.
• Smell
  • Urine odor may reveal health information. Patients with diabetes may have a sweet or fruity urine odor due to the presence of ketones (organic molecules with a specific structure) or glucose.
  • Fresh urine has a mild odor, whereas aged urine has a stronger odor similar to that of ammonia.
  • Foul-smelling urine may be seen in urinary infections.
• The pH
  • The pH of normal urine ranges from 4.6 to 8, with a typical average of about 6.0.
  • Diet accounts for a large portion of the variation.
  • High protein diets, for example, produce more acidic urine, whereas vegetarian diets produce more alkaline urine (both within the typical range of 4.6 to 8).
• Density
  • Specific gravity or density of normal urine ranges from 0.001 to 0.035.
• Turbidity
  • The turbidity of the urine sample is subjectively determined and reported as clear, slightly cloudy, cloudy, opaque, or flocculent.
  • Fresh urine is typically clear or slightly cloudy.
  • Excess turbidity is caused by the presence of suspended particles in the urine, and the cause is usually determined by microscopic examination.
  • Increased cells, urinary tract infections, or obstructions are common causes of abnormal turbidity.

Abnormalities in any of these physical characteristics could indicate disease or a metabolic imbalance. These issues may appear superficial or minor, but they can be symptoms of more serious diseases, such as diabetes mellitus or kidney damage.

1. Visual observation test:
   • The color, clarity, and odor of the urine are all evaluated visually.
   • Fresh urine should be pale and nearly clear.
   • Darker yellow urine indicates that the patient's body is dehydrated, and they are not drinking enough water.
   • Yellow urine is also seen in people who take multivitamins and other medications.
   • Red urine can be caused by the presence of blood or the consumption of red dye or foods, such as beets, rhubarbs, blueberries, and so on.
   • Bilirubin can cause yellowish-brown or greenish-brown urine.
   • Urine clarity is classified as clear, slightly cloudy, cloudy, or turbid.
   • Cloudy or frothy urine may indicate the presence of mucus, sperm in men, urine crystals, blood cells, or an excess of protein.
   • Fresh urine usually has a mild odor, but if it has a fishy odor, it may indicate a urinary tract infection.
   • A pear drop or acetone-like odor in the urine may indicate ketones, raising the possibility of ketoacidosis in a diabetic patient.
2. Chemical or dipstick test: A chemical exam looks for about nine substances that can give you information about your overall health and the presence of any illnesses. 
   • Ready-to-use test strips with test pads can be dipped into urine to detect the presence of specific chemicals. Within seconds, the chemical reactions change the colors of the strip.
   • The degree of a color change indicates whether the substance is present in a small or large amount.
   • The most common chemical reactions that are tested for are:
     • Acidity (pH):
       • Indicates whether the urine is acidic or alkaline. The pH of the body can range from four to eight depending on its acid-base status. Usually, the pH of urine is about six.
       • Alkaline urine could be caused by urinary tract infection or a diet high in dairy and vegetables.
       • Acidic urine could be caused by a high-protein diet or kidney stones (because it causes the formation of crystals).
     • Specific gravity (SG):
       • The concentration of urine is measured, which indicates how hydrated a person is. It is usually between 1.001 and 1.035.
       • Dehydration can be indicated by highly concentrated urine.
       • If the urine is found to be very dilute, this could be due to a high fluid intake, diabetes insipidus, high calcium levels, kidney disease, or low antidiuretic hormone levels.
     • Protein:
       • Protein molecules are typically too large to pass through the urine.
       • Proteinuria or the presence of protein in the urine indicates that the kidney's filtration system has been damaged, or the patient has hypertension, diabetes, or preeclampsia.
     • Bilirubin: An indicator of broken red blood cells that are not being removed by the liver indicates liver disease, bile duct blockage, gall bladder stones, or other conditions.
     • Nitrites: If bacteria are converting nitrate to nitrite, this compound is present. As a result, it could point to a urinary tract infection.
     • Glucose: Usually a sign of diabetes but can also be seen in pregnant women or those on corticosteroids.
     • Ketones:
       • Molecules that form when there is an abnormal breakdown of fat, can occur because of fasting, starvation, prolonged vomiting or diarrhea, or specific diet or uncontrolled diabetes.
       • High ketone levels in diabetic patients can cause the blood to become acidic, resulting in a serious complication called diabetic ketoacidosis.
     • Leukocyte esterase: A test for the presence of white blood cells or pus cells (also called pyuria), which are indicators of an infection.
     • Blood (also called hematuria): It could be an indication of an infection, kidney disease, kidney stones, prostate cancer, certain medications, or even strenuous exercise.
3. Microscopic examination: Urine is examined under a microscope to identify and count all types of cells, crystals, and bacteria. If the vial or dipstick exam is found to be abnormal, it is usually ordered.
   • This examination looks for these five things:
     • Red blood cells (RBCs)
       • A high number of RBCs in the urine can indicate the presence of blood, which is called hematuria.
       • Blood can enter the body through the kidney, ureter, bladder, or urethra.
       • Hematuria can be caused by urinary tract infections, kidney stones, kidney inflammation, an enlarged prostate, prostate cancer, sickle cell anemia, and other conditions.
       • The occasional presence of RBCs is not uncommon, but it necessitates further investigation.
     • White blood cells (WBCs)
       • When found in the blood, it can indicate urinary tract inflammation or infection.
       • If bacteria are present, it is most likely a urinary tract infection.
       • WBCs can occasionally be seen as a result of vaginal secretion contamination. 
     • Bacteria, yeast, or parasites
       • If the urine is collected as a clean catch, these organisms should not be seen.
       • If microbes are seen, they are reported as few, moderate, or numerous as seen under a high power field.
       • Bacteria can indicate a urinary tract infection, which can lead to kidney infection.
       • Women who have a vaginal yeast infection are more likely to have yeast.
       • Trichomonas vaginalis is an indicator of parasitic infection (usually in women) and is sent for trichomonas testing for confirmation.
     • Crystals
       • Nonspecific crystals in small amounts or if not tested freshly (within one to two hours, kept in cold temperatures or with low pH) are considered normal.
       • However, specific crystal formation is observed because of kidney stone types.
       • Certain antibiotics and antiviral medications can cause urine crystals to form.
     • Epithelial cells
       • Epithelial cells that line the bladder and urethra are visible in cases of infection, inflammation, and cancer.
       • According to the low power field, they are reported as few, moderate, or many.

Depending on the patient's symptoms and suspected illness, a different urine sample may be prescribed.

The following are the various test samples that a doctor may request:

• 24-hour collection:
  • Urine is collected for 24 hours because the chemicals in the urine can change.
  • This is frequently used to detect steroid use, white blood cells, electrolytes, and urine osmolarity (solute and water ratio).
• First-morning sample: This is mostly used to test for pregnancy by looking for hCG levels. A fasting sample is used to test glucose levels.
• Midstream urine sample: Is required for bacteria culture.
• Random sample: This is used for mostly screening purposes. A catheter sample is taken from a patient who has a catheter and is suspected of having a urinary tract infection.

The proper way to provide a urine sample is simple but not widely known. It is referred to as the clean-catch method. This method ensures that no normal bacteria that live on the skin or in vaginal secretions are present.

• A catheter is inserted to collect urine from people who are unable to provide a sample in this manner (babies, hospitalized, or comatose patients). 
• Inform your doctor if you are menstruating. 

Here are the steps for collecting a midstream clean-catch urine sample.

• Use a cleansing wipe or water and mild soap to clean the area around the urinary opening.
• For men, the tip of the penis should be spread and wiped front to back, whereas, for women, the external labia should be spread and wiped front to back.
• Begin urinating and then stop in the middle. Collect approximately 30 to 60 mL or fill the container to 3/4th full. Close the container's lid.
• Wash your hands and place the container in a bag to be given to the recipient.

Although there is a wide range of what is considered normal in terms of urine color, odor, and frequency, it is critical to note any sudden changes in what appears to be normal for you.

It is a good idea to practice preventive urinary health habits, such as not holding your bladder when you need to go, as well as drinking plenty of water throughout the day, every day.

Though these actions may appear to be small, they can be significant steps toward maintaining bladder and urinary tract health for years to come.