Hyponatremia (low sodium in the blood)

Overview

Mild low sodium may cause no symptoms. Fast or severe drops can cause brain swelling.

Correcting it too fast can also harm the brain, so it's done in a hospital.

Symptoms

Common signs:

• Nausea
• Headache

Less common

• Confusion
• Muscle cramps

Look up a symptom: Headache · Nausea · New confusion or not acting like themselves

When to get medical care

Causes

Water and salt imbalance.

Does it spread or run in families?

• It isn't contagious. You can't catch it from someone else.

Who is more likely to get it

• Older adults
• Marathon runners

Possible complications

• Seizures: With very low sodium
• Osmotic demyelination (central pontine myelinolysis): If corrected too fast

Diagnosis

A clinician asks about your symptoms and may order tests.

The exam

A physical exam.

Tests

Tests, if needed:

• Blood sodium:

Treatment

Treatment depends on the cause and how severe it is.

Self-care

• Don't overdrink water during exercise
• Review medicines

Which doctor treats this

• Start with your primary care provider (family doctor or internist).
• They may send you to a nephrologist (kidney doctor).

Children, pregnancy, and older adults

• Older adults: Higher risk, especially on water pills.

Pregnancy and breastfeeding

• If you're pregnant or planning to be, tell your prenatal provider about this condition.
• Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
• Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
• Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Most cases improve when the cause is treated.

Getting ready for your visit

Bring a list of your symptoms and medicines.

What to bring

• A list of your medicines and supplements
• Notes on when symptoms started and what makes them better or worse

Questions to ask

• What's causing this?
• What treatment do you recommend?
• Could my medicines cause this?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Hyponatremia (low sodium in the blood)