Hold the salt! Even chicken soup isn't sacred.

The time-honored home remedy can cause a rare complication called hypernatremia, or abnormally high sodium content in the blood, four San Francisco doctors report in The New England Journal of Medicine.

It all boils down to too much salt in the soup. Not just chicken soup -- any kind.

A 75-year-old woman with diabetes was asked to drink "salty broth" when she was taken off a diuretic drug, the doctors report. She had to be hospitalized when she became delirious after drinking several bowlfuls of salt-supplemented soups, including chicken with vegetable, in one day. She was given hypotonic fluids, which dilute the salt in the blood, and quickly returned to normal.

Usually, the body balances intake of high-salt foods and drinks by excreting the salt overload, but too much salt consumed too rapidly can overwhelm the body's ability to get rid of the excess.

A rare complication such as this is hardly an indictment of chicken soup, but yet another reminder that too much of a good thing can be risky.

"Although chicken soup should still be enthusiastically recommended for many illnesses," they write, "this case demonstrates that overzealous administration, as in any therapeutic intervention, is not without hazard.