Suspect acidity if you:
* take excessive strenuous exercise, which causes lactic acid to accumulate in the blood
* are diabetic, which tends to cause acidosis through loss of potassium, sodium and ketones in the urine
* suffer from chronic diarrhoea, which can cause acidosis
* have kidney problems, which can also cause acidosis (Kidney Int Suppl, 1999; 73: S85-8)
* follow the ketogenic diet, which works for epileptics, but has a deliberately acidifying effect
* are even mildly lactose-intolerant, as dairy products can cause lactic acidosis (Rose BD, Post TW. Clinical Physiology of Acid-Base and Electrolyte Disorders, 5th edn. New York, NY: McGraw-Hill, 2001).

If you are acidic (which is most likely):
* find out your metabolic type (see box, page 8)
* eat more ‘acidic’ foods if you are oxidative-dominant (need more protein to feel well) and more alkalinising foods if you are autonomic-dominant (need more carbohydrates to feel well)
* drink plenty of water; alkaline water is recommended by many practitioners, although its additional value is not yet clinically proven
* supplement with potassium bicarbonate
* cut down on salt, or add potassium citrate to it (Eur J Nutr, 2001; 40: 200-13)
* cut down on alcohol
* cut down on refined carbohydrates
* watch your intake of sugar and even fructose, which can cause acidosis when given intravenously
* supplement with vitamins B1 (thiamine) and B2 (riboflavin), both of which can help to correct severe acidosis. One of the hidden and largely unknown effects of a thiamine deficiency is metabolic acidosis. In one study of workers complaining of weakness and oedema in the legs, all were found to be deficient in thiamine (J Emerg Med, 2004; 26: 301-3).
* check your medications, as many drugs like aspirin, iron, epinephrine and metformin can cause acidosis (Borron SW. Lactic acidosis. Emedicine, 7 April 2005).

Suspect alkalinity if you:
* take steroids, diuretic drugs, antacids or laxatives (Chapter 11: Acid-base disturbances, in Bennett JC, Plum F, eds. Cecil Textbook of Medicine, 20th edn. Philadelphia: WB Saunders, 1996)
* have a kidney disorder.