Original Editors - Jordan Benock & Riley Benock from Bellarmine University's Pathophysiology of Complex Patient Problems project.
- 1 Definition/Description
- 2 Prevalence
- 3 Characteristics/Clinical Presentation
- 4 Associated Co-morbidities 
- 5 Medications
- 6 Diagnostic Tests/Lab Tests/Lab Values
- 7 Etiology/Causes
- 8 Systemic Involvement
- 9 Medical Management (current best evidence)
- 10 Physical Therapy Management (current best evidence)
- 11 Differential Diagnosis
- 12 Case Reports/ Case Studies
- 13 Resources
- 14 References
Fluid excess can occur in two main ways in the body, water intoxication and edema. 
Water Intoxication - The result of an excess of extracellular water without having an excess of solutes. Due to this imbalance, the extracellular fluid (ECF) becomes diluted causing water to move into cells to equalize solute concentration on each side of the cell. Hyponatremia, a potentially lethal situation, may occur if high volumes of water are consumed without solute replacement. 
Edema - The excess of both solutes and water, which is also termed isotonic volume excess. The additional fluid is retained in the extracellular compartment resulting in fluid accumulation in the interstitial spaces. 
Water intoxication is seen in a variety of situations, but most commonly occurs in:
- Patients suffering from psychogenic polydipsia (compulsive water drinking) which is often associated with mental illness 
- Army recruits/members 
- Endurance athletes 
In a study by Almond et al. of the 2002 Boston Marathon it was found that: 
- 13% of 488 runners studied had hyponatremia (serum sodium concentration of 135 mEq/L or less)
- 0.6% had critical hyponatremia (serum sodium concentration of 120 mEq/L or less)
In a study by Speedy et al. of athletes who finished an ultramarathon, it was found that: 
- 18% of 330 athletes were hyponatremic
- 3.3% were classified as being severely hyponatremic
Water Intoxication Clinical S&S: 
Water intoxication presents with symptoms that are largely neurologic due to the shifting of water into brain tissues and resultant dilution of sodium in the vascular space.
- Decreased mental alertness
- Poor motor coordination
In severe imbalances:
- Sudden weight gain
- Warm, moist skin
- Signs of increased intracerebral pressure
- Slow pulse
- Increased SBP (more than 10 mm Hg)
- Decreased DBP (more than 10 mm Hg)
- Mild peripheral edema
- Low serum sodium
- Low hematocrit
Edema Clinical S&S: 
- Weight gain (primary symptom)
- Excess fluid
- Dependent edema (accumulation of fluid in lower parts of the body)
- Pitting edema
- Increased blood pressure
- Neck vein engorgement
- Effusions (pulmonary, pericardial, peritoneal)
Associated Co-morbidities 
- Liver disease
- Kidney dysfunction
- SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion)
- Schizophrenia and other psychological disorders
- Endocrine disorders
|Drug Name||Type of Drug||Used For||Side Effects|
|Chlorothiazide  & Hydrochlorothiazide ||Diuretic||
|Conivaptan (Vaprisol) ||V1A and V2 vasopressin receptor antagonist||
|Tolvaptan ||Vasopressin V2 receptor antagonist||
Diagnostic Tests/Lab Tests/Lab Values
Below are some of the most common laboratory tests that are used to assess a person’s hydration status:
- Serum Osmolality Tests are used as a measurement to determine the number of solutes present in the blood (serum). These tests are typically ordered to evaluate hyponatremia, which is generally a result of sodium lost in the excretion of urine or excess fluid in the bloodstream. Excess fluid in the bloodstream can be caused by water retention, drinking excessive amounts of water, decreased ability of the kidneys to produce urine, and the presence of osmotically active agents such as glucose. 
- Osmolality decreases with overhydration 
- Sodium Tests are also used to measure amounts of sodium in the blood (hypernatremia and hyponatremia). They are ordered when there is a suspected electrolyte imbalance, which could result in confusion, lethargy, weakness, decreased urinary output, and muscle twitching just to name a few. 
- Hematocrit Tests measure the percentage of blood that is comprised of red blood cells. Often times, this test is ordered as a part of a complete blood count. 
- BUN (Blood Urea Nitrogen) Tests measure the amount of urea nitrogen in the blood and are typically ordered to evaluate kidney function. However, they can also be used in other medical conditions such as diabetes, CHF, MI, severe burns, and overhydration. 
Due to the etiologic complex, symptoms, and outcomes that are related to the two major forms of fluid excess being substantially different, they will be broken down individually. 
Occurs most often in older adults recovering from the flu who drink additional water with associated diarrhea and vomiting, or in athletes who have lost compious amounts of body fluids and replaced them solely with water.
Can occur from many different situations, most commonly:
Digestive System - Liver disease is one of the primary causes of serum protein loss, which in turn causes edema in the extremities or abdomen (ascites). 
Integumentary System - This system can be involved in a variety of ways. Much like liver disease, burns can be a common cause of serum protein loss, leading to edema in the body. In addition, edema itself can cause signs and symptoms of redness, shiny skin, and tight or stiff skin. 
Genitourinary System - The kidneys play a vital role in fluid and electrolyte balances. As age increases, the renal mass and glomerular filtration rate (GFR) decrease, which could in turn lead to the inability of the kidney to excrete free water when faced with fluid excess, causing hyponatremia. 
Cardiopulmonary System - An increase in intravascular fluid can result in CHF as well as increased pulse and respiration, whereas an increase in extravascular fluid may lead to edema, ascites, or pleural effusion. Also, an excess of water will occur when there is an overabundance of water in the interstitial spaces or within the blood vessels (hypervolemia). This can result in a fluid shift, where vascular fluid moves to interstitial or intracellular spaces, or vice versa. 
Nervous System - Water intoxication will largely present with neurological symptoms due to the shifting of water into brain tissues causing a resultant dilution of sodium in the vascular space. 
Endocrine System - Increased secretion of ADH which in turn causes excess solute free fluid. 
Medical Management (current best evidence)
- Hypertonic Saline- a solution that contains sodium chloride and is given to patients to treat severe hyponatremia (serum sodium levels below 120 mEq/L). These patients typically present with severe and potentially life-threatening symptoms such as: coma, seizures, and new focal neurological findings. 
- Continued lab and blood tests to monitor hydration status and electrolyte levels. 
- Managing edema
- Controlling high BP (common in patients with edema) 
Physical Therapy Management (current best evidence)
Physical therapy management is largely responsible for patient education and edema control in these individuals. Below are some common physical therapy treatment strategies:
Education on fluid consumption: 
- Educate patient on proper fluid consumption/restrictions to prevent extracellular fluid accumulation and water intoxication
- Educate patient on how to monitor daily fluid consumption by measuring out how much fluid you drink throughout the day
- Avoid constricting vessels to prevent venous pooling (don’t cross legs, wear tight clothing, etc.)
- Implement appropriate activity and position changes to prevent fluid accumulation in dependent areas
- Implement compression to the edematous extremity
- Elevating the edematous extremity to increase venous return and reduce edema
- The use of electrical stimulation and exercise to help reestablish the normal circulatory flow through muscle contractions
- Massage can reduce edema by increasing venous and lymphatic flow
Note: Some of the strategies to reduce edema may be contraindicated in CHF
Additional benefits may be achieved through the combination of multiple techniques
The following are some of the most common diagnoses that present with similar signs and symptoms of excess fluid/intoxication:
- Electrolyte imbalances
- Endocrine disorders
- Liver disease
- Kidney dysfunction
- Vascular pathology
Case Reports/ Case Studies
add links to case studies here (case studies should be added on new pages using the case study template)
- Goodman CC, Snyder TEK. Differential diagnosis for physical therapists: screening for referral. 5th ed. St. Louis: Elsevier Saunders, 2013.
- University of Maryland Medical Center. Lower Leg Edema. http://www.umm.edu/graphics/images/en/8857.jpg (accessed 20 March 2013).
- Farrell DJ, Bower L. Fatal water intoxication. JCP 2003;56:803-4. http://jcp.bmjjournals.com/content/56/10/803.2.full (accessed 22 March 2013).
- Rosner MH, Kirven J. Exercise-associated hyponatremia. CJASN 2007;2:151-61. http://cjasn.asnjournals.org/content/2/1/151.full (accessed 22 March 2013).
- MedlinePlus. Chlorothiazide. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682341.html (accessed 22 March 2013).
- MedlinePlus. Hydrochlorothiazide. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682571.html (accessed 22 March 2013).
- DailyMed. Vaprisol (conivaptan hydrochloride) solution. http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=87713d73-5dcc-4158-8890-60efdbd28c05 (accessed 22 March 2013).
- MedlinePlus. Tolvaptan. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a609033.html (accessed 22 March 2013).
- Lab Tests Online. Osmolality. http://labtestsonline.org/understanding/analytes/osmolality/tab/test (accessed 21 March 2013)
- Goodman CC, Fuller KS. Pathology: implications for the physical therapist. 3rd ed. St. Louis: Saunders Elsevier, 2009.
- Lab Tests Online. Sodium. http://labtestsonline.org/understanding/analytes/sodium/tab/test (accessed 21 March 2013).
- Lab Tests Online. Hematocrit. http://labtestsonline.org/understanding/analytes/hematocrit/tab/test (accessed 21 March 2013)
- Medline Plus. Hematocrit. http://www.nlm.nih.gov/medlineplus/ency/article/003646.htm (accessed 21 March 2013).
- Lab Tests Online. BUN. http://labtestsonline.org/understanding/analytes/bun/tab/test (accessed 21 March 2013)
- American Society of Clinical Oncology. Edema or fluid retention. http://www.cancer.net/all-about-cancer/treating-cancer/managing-side-effects/edema-or-fluid-retention (accessed 22 March 2013).
- Medscape. Should hypertonic saline be used to treat a patient with hyponatremia? http://www.medscape.com/viewarticle/586797 (accessed 23 March 2013).
- Elsevier. Fluid volume excess - hypervolemia; fluid overload. http://www1.us.elsevierhealth.com/MERLIN/Gulanick/archive/Constructor/gulanick22.html (accessed 23 March 2013).
- Prentice WE. Therapeutic modalities in rehabilitation. 4th ed. China:McGraw-Hill Companies, 2011.