There can be other reasons for those dark circles, however. Apart from needing more sleep, they could indicate poorly functioning kidneys. Follow a kidney-friendly diet by drinking at least 2 litres of bottled or filtered water every day, eating more raw foods (aim for 75 per cent) and reducing your intake of animal proteins, as too much can put stress on the kidneys. Alternative protein sources include peas, beans, lentils, nuts, seeds, millet, quinoa, soya and wholegrains. Foods that support the kidneys include garlic, potatoes, asparagus, parsley, watercress, celery, cucum- bers and papaya, plus lentils, seeds and soya, which contain kidney-friendly arginine. It' s also important to reduce your intake of potassium and phosphates. Avoid salt and potassium chloride (a salt substitute), beet greens, chocolate, cocoa, eggs, fish, meat, spinach, rhubarb, Swiss chard and tea, and limit your consumption of bananas to no more than three a week.

Additional considerations include checking for heavy metal toxicity, as heavy metals are very harmful to the kidneys and need to be eliminated if present. A nutritionist can arrange a hair mineral analysis to check this. Note that if you have severe back pain, this could indicate kidney stones or other problems with your kidneys; you should see a doctor immediately to check for these. However, by far the most common cause of dark circles is an allergy.