Diuretics are the simplest form of masking agent. These are substances that help with passing fluid rapidly, diluting the urine and evading detection. They are normally used in treatment for hypertension and oedema.
Diuretics are often used in weight classification sports when it is vital to drop weight quickly. The side effects of diuretics include heart arrhythmia, kidney problems, tiredness, dehydration, frequent urination and muscle cramps. Examples of diuretics include Diucardin (hydroflumethiazide), Hydromox (quinethazone), Naturetin (bendroflumethiazide), Aldactone (spironolactone), Dyrenium (triamterene), and Midamor (amiloride).