The kidneys play several crucial roles in the body, notable among which is the formation of urine. Through the medium of urine, the kidneys eliminate excess water, toxins and nitrogenous waste products of metabolism like urea from the body. As simple as this pivotal function may appear, its failure results in the accumulation of these toxic substances within the body with attendant disastrous consequences on the health and wellbeing of the affected individual.
Fortunately, the colour of the urine can serve as a window that provides valuable information regarding the functioning of the kidneys and body as a whole. Hence, any change noticed in urine colour should never be ignored. The normal urine is clear with a straw yellow to amber colour accounted for by a pigment called urochrome. With a 95% water composition, the urine also contains other substances such as urea, uric acid, salts, minerals and so on.
It’s worthy of note that a good number of medical conditions find expression in the colour of the urine ranging from dehydration which is relatively mild and easily corrected to kidney disorders which may be potentially life-threatening e.g renal cancers. Evidently, if the apparent change in your urine colour is due to dehydration, increasing your daily water intake will definitely do the trick and restore your urine to its normal colour. However, persistent urine discolouration such as bloody urine is an alarm sign that necessitates immediate presentation and further assessment at the hospital. Below is a discussion of various possible colours of your urine and what they could mean for your health:
1. Straw yellow to amber
Generally, when your urine is pale yellow to amber coloured, it shows you are well hydrated and there is really nothing to worry about. However, dark shades of yellow such as deep yellow or brown/honey could be pointers to dehydration. More often than not, the urine colour normalises as you increase your fluid intake
2. Transparent or colourless
A transparent or colourless urine points to excessive dilution of urine due to overhydration, use of diuretics (drugs that enhance fluid loss from the body) or diabetes insipidus, a medical condition that occurs as a result of a failure of the posterior pituitary gland to secrete sufficient Antidiuretic Hormone (ADH) or a failure of the kidneys to respond to the hormone leading to passage of copious quantities of overdiluted urine. It’s important to note that if overhydration due to excessive drinking and use of diuretic medications has been excluded, it becomes necessary to consult your doctor for further evaluation.
3. Red or Pink
Red bloody urine (haematuria) is often an alarm sign that usually warrants further expert evaluation because it usually points to problems along the urinary tract ranging from infections, stones and cancers to trauma. However, certain things like beets, blueberries and red dyes may also add a red colour to the urine. In addition, the presence of haemoglobin in the urine (haemoglobinuria) due to several conditions like Glucose-6 Phosphate Dehydrogenase (G6PD) deficiency, sepsis and malaria can colour the urine with a tinge of dark red also described as coke-coloured.
4. Cloudy or milky urine
Passage of cloudy or milky urine often suggests a bacterial urinary tract infection especially when it is accompanied by a burning sensation during urination (dysuria) and/or frequency. The presence of lymphatic fluid in the urine (chyluria) can also give a similar picture.
5. Blue or Green
This is a relatively rare urine colour that could be quite scary. It may be observed in individuals suffering from porphyria, a genetic enzymatic disorder due to a defect during the synthesis of red blood cell haemoglobin. However, artificial colours in foods or drugs as well as medications like methylene blue can also add such a strange colour to the urine. In rare instances, some unusual urinary tract infections can give rise to bluish or greenish urine.
A black urine is mostly seen in alkaptonuria, a rare autosomal recessive disorder of tyrosine metabolism leading to accumulation of homogentisic acid in the blood which is then rapidly cleared by the kidneys through the urine. This accounts for the black discolouration of the urine in this condition.
Orange discoloration of the urine can occur after taking some medications like rifampicin and Pyridium. Rifampicin is a first-line anti-tuberculosis drug. In the same vein, consuming orange foods like carrots can add an orange tinge to the urine.
8. Dark Brown
When the urine colour is dark brown, it may be the result of an accumulation of conjugated bilirubin due to severe liver damage. A liver disorder should be suspected if dark brown urine is accompanied by yellowness of the sclera and skin (jaundice) or passage of pale stools. Furthermore, the urine may also appear brown on account of extreme dehydration or consumption of fava beans.