Diuretics are a class of medication that removes excess sodium and fluids from your body. Diuretic drugs, sometimes called “water pills,” are used to treat hypertension (high blood pressure). High blood pressure can be a contributing factor for various forms of heart disease, including heart attack.

Scientific studies as early as the 1960s have shown, as cited in a 2005 issue of Circulation, that diuretics are effective in preventing heart attack and stroke in many individuals when chosen as a treatment method for hypertension. Certain foods and herbs also possess diuretic effects; that is, they make you urinate more often to excrete excess fluid.

Pharmaceutical Diuretics

Pharmaceutical diuretics, i.e. prescription medications, are grouped into three main forms:

  • thiazide: includes metolazone (brand name: Zaroxolyn), indapamide, hydrochlorothiazide (brand name: Microzide), and chlorothiazide
  • loop: includes Furosemide (brand name: Lasix), ethacrynic acid (brand name: Edecrin), torsemide (brand name: Demadex), and bumetanide
  • potassium-sparing: Amiloride, triamterene (brand name: Dyrenium), eplerenone (brand name: Inspra), and spironolactone (brand name: Aldactone)

Each of the three types of medication increases the amount of sodium you excrete through urination, but affect different areas of your kidneys. Your kidneys are the filters through which toxins are flushed from your body, along with excess fluid. When you take a diuretic medication, the drug signals to your kidneys that you need to get rid of more sodium. Water binds to the sodium and is excreted during urination, leaving you with a lower blood volume. The lower volume reduces the force with which blood flows through your blood vessels, thus lowering your blood pressure.

Thiazide and loop diuretics may also cause you to lose potassium in addition to water and sodium. Potassium is an electrolyte crucial to retaining healthy fluid levels and strong bones. Your doctor may advise you to take a potassium supplement or to eat foods rich in the nutrient, such as bananas or raisins, to combat low potassium levels. Potassium-sparing diuretics do not pose as much as a threat to your potassium levels. 

Your medication may contain more than one kind of diuretic agent in a single pill or dose. The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends thiazide-based drugs as the primary treatment option for people who have hypertension-related heart disease. However, your doctor will tailor your drug regimen to your specific health concerns.

Natural Diuretics

Food and herbal supplements can have a diuretic effect on your body, increasing your urine output. Natural diuretic aids may be beneficial to your high blood pressure, but should be used with caution. Taking a natural diuretic, even unintentionally through your normal diet, along with a pharmaceutical could lead to dehydration (an excessive loss of essential minerals) or other potentially harmful interactions. Examples of natural diuretics include:

  • ginger root: brewed into a tea or used as a spice in cooking, it can also ease stomach upset
  • celery: its water content is high, and its sodium and potassium content stimulates urine production
  • dandelion: anecdotal studies suggest that it increases urine output

Speak to your medical team to learn more about which natural diuretics are appropriate to your condition.

Risks and Side Effects

Diuretics are generally safe for most people when taken as prescribed.

The most common side effect of diuretics is increased urination. Your potassium, glucose, and cholesterol levels may fluctuate depending on the type of diuretic you’re taking, so your physician may run blood tests to measure your levels. Other side effects may include:

  • headaches
  • dizziness or lightheadedness
  • sleeping difficulties
  • muscle cramping or weakness
  • increased thirst
  • irregular menstruation
  • impotence
  • gout

Side effects are likely to decrease over time, according to the Mayo Clinic. Consult your medical care provider if you experience uncomfortable or prolonged adverse effects associated with diuretic use. Your physician may adjust your dosage or switch you to a different type of diuretic medication.