The Role of Water Inside the Body

From the MASSAGE Magazine article, “Hydrotherapy for the Massage Practitioner,” by Richard Eidson, in the March 2009 issue. Article summary: Hydrotherapy  involves bringing water into contact with the client’s body in a controlled manner, to produce specific therapeutic transformations.

Water plays an essential role in every level of functioning of the physiology of the human body. In someone who weighs 145 pounds, 60 percent water in the body would equal 10 gallons, or 84 pounds. Of this, 6.6 gallons are located inside the 100 trillion cells of the body, 2.7 gallons are in the interstitial fluid (including lymphatic fluid) that surrounds these cells and 0.7 gallons are in the blood plasma. An additional small amount of water is found in the cerebral spinal fluid, synovial joints and aqueous humor.

To maintain continual circulation to each of the 100 trillion cells of the body, the heart must pump approximately 3,600 gallons of blood each day through a system of arteries and veins greater than 60,000 miles long to 10 billion capillary beds, where there is an exchange with the interstitial fluid and cells of the body. Each day, approximately 5 gallons of blood plasma will flow into the interstitial fluid, 4.25 gallons will return to the blood plasma via the capillaries and 0.75 gallons (3 quarts) will return via the lymphatic system.

Maintaining optimal levels of hydration each day and thereby preventing dehydration, as well as intake of water from quality sources, are essential components of health and wellness. Over every 20 days, an individual will naturally lose, on average, more than 105 lbs. (12.5 gal.) of water and replace that amount with water from beverages, plain water and food. This also shows why it is essential that the daily amount of water intake be adequate and that is comes from high-quality, natural sources.

—Richard Eidson