Colour changes that can reveal hidden health problems

The shade of your urine can reveal everything from simple dehydration to kidney disease and even cancer

- BY TANITH CAREY

Urine is made when your kidneys flush out extra water and water-soluble waste products like salts, hormones and minerals your body no longer needs. It gets its yellow colour because it contains urochrome, an end product of the greenish-coloured liquid, bile. Bile is what is left over when red blood cells, which die after 120 days, are broken down.

It is stored in the gallbladder and most of it is excreted through the intestines and leaves the body in the faeces.

However, about 10% of the bile goes back into the bloodstream and is filtered by the kidneys, where it is converted into urochrome, an indigestible yellow pigment. In a normal sample of urine, 96% is water. Up to 4% is waste, including the pigments which give urine its colour.

Wendy Lee, lead pharmacist at Well Pharmacy, one of the UK's largest pharmacy chains, says: "A healthy person's urine should be pale yellow in colour.

"Of course, this can vary depending on how much and what you drink, the temperature where you are, if the drink is caffeinated or if you are drinking alcohol."

"Do keep an eye on the colour of your urine," adds GP Dr Deborah Lee of online pharmacy doctorfox.co.uk.

"The colours to be concerned about are red-pink, brown, orange, green or blue."

Although different colours are usually nothing to worry about, if the colour is very extreme or lasts a long time, visit your local pharmacist or GP, adds Wendy.

BRIGHT YELLOW

If your urine has suddenly turned bright yellow, the most likely cause is vitamin supplements.

In natural foods, like fruit and vegetables, vitamins like B and C are only found in small amounts.

For example, the recommended adult daily intake of vitamin B complex - also known as Riboflavin - is up to 1.3mg at one time - the same found in three eggs, according to studies by scientists at Florida Atlantic University.