Health information to help you understand symptoms. It isn't a diagnosis.About OwieClear
Check symptoms

Lambert-Eaton syndrome

Also called: Lambert-Eaton syndrome

An immune disease causing leg weakness that improves briefly with use, sometimes linked to lung cancer.

CheckFor lung cancer

Overview

About half of cases are linked to small cell lung cancer, which may be found later.

The immune system blocks signals from nerves to muscles.

Symptoms

Common signs:

  • Leg weakness

Less common

  • Dry mouth
  • Constipation
  • Droopy eyelids

When to get medical care

Call 911Trouble breathing.
Get care todayNew or worse symptoms, or symptoms with fever.
See a doctor soonSymptoms that last or keep coming back.

Causes

Immune.

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

  • Smoking

Possible complications

Diagnosis

A clinician asks about your symptoms and may order tests.

The exam

A physical exam.

Tests

Tests, if needed:

  • Antibody test:
  • Chest CT:

Treatment

Treatment depends on the cause and how severe it is.

Self-care

  • Pace activities
  • Rest

Prevention

To lower your risk or prevent problems:

  • Don't smoke

Which doctor treats this

  • Start with your primary care provider (family doctor or internist).
  • They may send you to a neurologist (brain and nerve doctor).

Living with it

Support groups and helplines

Children, pregnancy, and older adults

  • Smokers over 50: Higher risk.

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

Treatment improves strength for many.

Treating cancer helps.

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?
  • How often should I be screened for cancer?

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 Lambert-Eaton syndrome

Sources

Last updated 2026-11-12.