High Blood Pressure and Water Intake

by Lisa Nelson, RD, LN Health Professional

Dehydration is a potential cause of low blood pressure (hypotension) due to decreased blood volume resulting in decreased pressure against artery walls. However, did you know not drinking enough water can lead to high blood pressure?

When you do not drink adequate water the body will compensate by retaining sodium. That should be a red flag as sodium is directly related to high blood pressure.

While sodium retention takes place, the persistent dehydration leads the body to gradually close capillary beds. (Capillary beds are a network of microscopic blood vessels where nutrients, gases, and waste are exchanged.) This leads to increased pressure places on arteries and a rise in blood pressure.

3 steps to prevent dehydration

Here are three steps you can take to prevent high blood pressure that is caused by dehydration.

1. Drink eight to ten 8-ounce glasses of water daily

If you already have high blood pressure, your goal may be even higher. However, if you have kidney issues, you should consult your doctor.

2. Don't drink too much

You can go overboard on water intake and the body can only take so much. If you currently do not drink a large quantity of water, increase your intake gradually so your body can adapt. Drinking more than 96 ounces of water daily can place increased stress on your digestive system and kidneys.

3. Drink water when you exercise

You need to replenish the water stores lost during exercise via sweat and evaporation. Be sure to drink adequate water before, during, and after exercise.

The American College of Sports Medicine recommends the following:

  • Drink 16 to 20 ounces of fluid two hours before exercise.

  • Drink 8 to 12 ounces of fluid 10 to 15 minutes before exercise.

  • Drink water every 15 to 20 minutes during exercise sessions that last less than an hour.

  • Never restrict fluids during exercise.

Lisa Nelson, RD, LN
Meet Our Writer
Lisa Nelson, RD, LN

Lisa Nelson RD, a registered dietitian since 1999, provides step-by-step guidance to lower cholesterol and lower blood pressure, so you can live life and enjoy your family for years to come. Lisa's passion for health comes from her own family history of heart disease, so she doesn't dispense trendy treatments; Lisa practices what she teaches in her own daily life. Because her own health is the foundation of her expertise, you can trust that Lisa will make it truly possible for you to see dramatic changes in your health, without unrealistic fads or impossibly difficult techniques.