Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Multiple Sclerosis Health Center

Font Size

Proposed Triggers of Multiple Sclerosis

Viral infection, injury, and pregnancy are the most frequently proposed triggers for multiple sclerosis (MS). But there is no scientific proof that they trigger MS in a person who does not already have the disease.

In someone who already has MS, a viral infection such as the flu can trigger a relapse. There is no proof that flu vaccination (or any other vaccination) increases the chance of a relapse. In fact, people with MS may want to consider getting an annual flu shot to avoid infection and any attacks it may trigger. But there is no evidence that the nasal spray vaccine is safe for people with MS. If you have MS, talk with your doctor about whether a nasal spray vaccine is right for you.

Studies have also shown that women with MS have:1

In people who have been diagnosed with MS, there is no proof that attacks or worsening of the disease is brought on by:

  • Insertion of hypodermic needles into the fluid surrounding the lower spine (lumbar puncture).
  • Surgery and anesthesia.
  • Emotional stress.


  1. Bennett KA (2005). Pregnancy and multiple sclerosis. Clinical Obstetrics and Gynecology, 48(1): 38-47.

ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Anne C. Poinier, MD - Internal Medicine
Specialist Medical ReviewerBarrie J. Hurwitz, MD - Neurology

Current as ofMarch 12, 2014

WebMD Medical Reference from Healthwise

Last Updated: March 12, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Today on WebMD

nerve damage
Learn how this disease affects the nervous system.
woman applying lotion
Ideas on how to boost your mood and self-esteem.
woman pondering
Get personalized treatment options.
man with hand over eye
Be on the lookout for these symptoms.
brain scan
worried woman
neural fiber
white blood cells
sunlight in hands
marijuana plant
muscle spasm