St. Luke's Hospital
Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
America's 50 Best Hospitals
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia

    Print-Friendly
    Bookmarks

    Hyponatremia

    Dilutional hyponatremia; Euvolemic hyponatremia; Hypervolemic hyponatremia; Hypovolemic hyponatremia

    Hyponatremia is acondition in which the amount of sodium (salt) in theblood is lower than normal.

    Causes

    Sodium is found mostly in the body fluids outside the cells. It is very important for maintaining blood pressure. Sodium is also needed for nerves, muscles, and other body tissuesto work properly.

    When the amount of sodium in fluids outside cells drops, water moves into the cells to balance the levels. This causes the cells to swell with too much water. Brain cells are especially sensitive to swelling, and this causesmany of the symptoms of hyponatremia.

    In hyponatremia, the imbalance of water to salt is caused by one of three conditions:

    • Euvolemic hyponatremia -- total body water increases, but the body's sodium content stays the same
    • Hypervolemic hyponatremia -- both sodium and water content in the body increase, but the water gain is greater
    • Hypovolemic hyponatremia -- water and sodium are both lost from the body, but the sodium loss is greater

    Hyponatremia can be caused by:

    • Burns that affect a large area of the body  
    • Diarrhea
    • Diuretic medicines, which increase urine output
    • Heart failure
    • Kidney diseases
    • Liver cirrhosis
    • Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
    • Sweating
    • Vomiting

    Symptoms

    Common symptoms include:

    • Confusion
    • Convulsions
    • Fatigue
    • Headache
    • Irritability
    • Loss of appetite
    • Muscle spasms or cramps
    • Muscle weakness
    • Nausea
    • Restlessness
    • Vomiting

    Exams and Tests

    The health care provider will perform a complete physical examination to help determine the cause of your symptoms. Blood and urine tests will be done.

    The following laboratory tests can confirm and help diagnose hyponatremia:

    • Comprehensive metabolic panel (includes blood sodium)
    • Osmolality blood test
    • Urine osmolality
    • Urine sodium

    Treatment

    The cause of hyponatremia must be diagnosed and treated. If canceris thecause of the condition, radiation, chemotherapy, or surgery to remove the tumor may correct the sodium imbalance.

    Other treatments depend on the specific type of hyponatremia.

    Treatments may include:

    • Fluids through a vein (IV)
    • Medication to relieve symptoms
    • Water restriction

    Outlook (Prognosis)

    The outcome depends on the condition that is causing the problem. Acute hyponatremia, which occurs in less than 48 hours, is more dangerous than hyponatremia that develops slowly over time. When sodium level falls slowly over days or weeks (chronic hyponatremia), the brain cells have time to adjust and swelling is minimal.

    In severe cases, hyponatremia can lead to:

    • Decreased consciousness, hallucinations or coma
    • Brain herniation
    • Death

    When to Contact a Medical Professional

    Hyponatremia can be a life-threatening emergency. Call your health care provider right away if you have symptoms of this condition.

    Prevention

    Treating the condition that is causing hyponatremia can help. If you play sports, drink fluids such as sports drinksthat contain electrolytes. Drinking only water while youare activecan lead to acute hyponatremia.

    References

    Skorecki K, Ausiello D. Disorders of sodium and water homeostasis. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, Pa.: Elsevier Saunders; 2011:chap 118.

    BACK TO TOP

          Tests for Hyponatremia

            Review Date: 4/14/2013

            Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.

            The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
            adam.com

            A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.


            Back  |  Top
            About Us
            Contact Us
            History
            Mission
            Locations & Directions
            Quality Reports
            Annual Reports
            Honors & Awards
            Community Health Needs
            Assessment

            Newsroom
            Services
            Brain & Spine
            Cancer
            Heart
            Maternity
            Orthopedics
            Pulmonary
            Sleep Medicine
            Urgent Care
            Women's Services
            All Services
            Patients & Visitors
            Locations & Directions
            Find a Physician
            Tour St. Luke's
            Patient & Visitor Information
            Contact Us
            Payment Options
            Financial Assistance
            Send a Card
            Mammogram Appointments
            Health Tools
            My Personal Health
            mystlukes
            Spirit of Women
            Health Information & Tools
            Clinical Trials
            Health Risk Assessments
            Employer Programs -
            Passport to Wellness

            Classes & Events
            Classes & Events
            Spirit of Women
            Donate & Volunteer
            Giving Opportunities
            Volunteer
            Physicians & Employees
            For Physicians
            Remote Access
            Medical Residency Information
            Pharmacy Residency Information
            Physician CPOE Training
            Careers
            Careers
            St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
            Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Patient Notice of Privacy Policies PDF Sitemap St. Luke's Mobile