It’s simple: the urine should be clear yellow, without a strong odor. Depending on its dilution, it can take on different “normal” shades, from almost transparent to darker yellow.

That said, any pronounced change in color, density or odor can indicate a health problem. The appearance of urine has also been used by doctors for centuries to decipher the state of health of their patients.

By playing a role of “purifier”, the urine evacuates the soluble waste filtered by the kidneys (present initially in the blood). It is therefore understandable that it says a lot about substances in the blood, whether they are excess protein, sugar, bacteria or other microbes.

Urine owes its yellow color to a pigment called urobilin, which results from the breakdown of hemoglobin.

When the urine is very clear, it is very diluted. On the contrary, if it is dark yellow, it is a sign that you are not hydrated enough (e).

The foods we eat can also influence the appearance of urine. This is particularly the case with beets, which can tint urine (and stool) pink. Asparagus, on the other hand, can quickly change the smell of urine. These changes are transient and not serious.

Changes in urine color, however, may indicate the presence of potentially serious disease. Without being exhaustive, here is a list of the colors that urine can take and the health problems associated with it:

• if the urine is brown: either it is very concentrated (you must therefore rehydrate as quickly as possible), or it may be a question of liver disease or porphyria, a metabolic disease which gives the urine a color ” port ”characteristic.
• if the urine is pink or red: unless you have eaten red berries, rhubarb or beets recently, the red color should lead to a consultation: it usually indicates the presence of blood in the urine. It can be a urinary tract infection, kidney infection, but also cancer or prostate problems. This is therefore an urgent reason for consultation.
• If the urine is orange: again, it may simply be too concentrated, or indicate a biliary or liver problem. Certain food dyes (sometimes contained in commercial vitamins) can also color urine orange, especially carotenes. Ditto for certain drugs, such as rifampicin, an antibiotic.

If the urine is bluish or greenish: this may be a rare genetic disease, or the effect of bacteria present in the urinary system (especially Pseudomonas aeruginosa). Some medicines can also stain urine, such as methylene blue (but also indomethacin, amitriptyline, triamterene, etc.).

• If the urine is gray or blackish: the blackening of the urine on contact with air is characteristic of the presence of homogentisic acid, caused by a rare genetic disorder called alkaptonuria.
• If the urine is whitish or milky: this may be the result of the presence of lipids in the urine (lipiduria) or the presence of chyle (chyluria), a fluid present in the lymphatic vessels of the small intestine (some parasites can cause chyluria).
• If the urine is foamy: it may be too much protein in the urine (proteinuria)

Finally, a change in the smell of urine should also lead to consult your doctor.

As we have seen, abnormal coloring of the urine can indicate the presence of a potentially serious disease, such as cancer.

Before you panic, ask yourself if you haven’t taken any unusual medicine or food that may stain your urine. If in doubt, quickly consult your doctor or pharmacist.

The treatment will obviously depend on the disease in question.