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What does hyponatremia mean?

Low blood sodium is called hyponatremia.

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  1. High blood sodium
  2. Low blood sodium ✔
  3. Low blood calcium

Why: Hyponatremia means the sodium in your blood is lower than normal. Drinking too much water during endurance events like marathons can dilute the sodium in your blood.

Huh, didn't know that: When sodium drops, water moves into cells, and brain cells are especially sensitive to the swelling.

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Why did the runner put a pinch of salt in their joke? It needed some seasoning.
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References

Answer: Low blood sodium. Hyponatremia means the sodium in your blood is lower than normal. Drinking too much water during endurance events like marathons can dilute the sodium in your blood.

  1. Low blood sodium | MedlinePlus Medical Encyclopedia medlineplus.gov/ency/article/000394.htm
    Low blood sodium is a condition in which the sodium level in the blood is lower than normal.
    Checked 2026-10-12.
  2. Hyponatremia | Mayo Clinic www.mayoclinic.org/diseases-conditions/hyponatremia/symptoms-causes/syc-20373711
    drinking too much water during endurance activities, such as marathons and triathlons, can also dilute the sodium content of your blood
    Checked 2026-10-12.

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