Painful vision loss, facial paralysis, limb weakness and persistent dizziness all indicate you should see a healthcare provider immediately

Like many diseases, multiple sclerosis (MS) affects everyone differently, bringing symptoms that can range from mild to severe. This autoimmune condition affects your central nervous system, causing issues like muscle weakness, vision changes, numbness and memory issues.

Certain early signs of multiple sclerosis should prompt you to seek treatment — and to ask whether you could be dealing with the beginning stages of this condition.

4 early signs of MS

There are a few hallmarks of early signs and symptoms of multiple sclerosis. They typically:

  • Last longer than 24 hours
  • Come on over a course of hours or days
  • Get worse before they get better

“These issues will generally feel unlike any others that you've experienced in your normal, day-to-day life,” says neurologist Robert Bermel, MD.

Dr. Bermel shares four potential signs and symptoms you should never ignore.

1. Painful vision loss in one eye

A common early sign of MS is optic neuritis, painful vision loss caused by inflammation in the optic nerve (the nerve that connects your eyes to your brain). It may feel like a dull ache or stabbing pain, and it may get worse when you move your eye.

“Vision-wise, people often describe it as ‘looking through smudged sunglasses’ on one side,” Dr. Bermel explains. “It’s typically the type of concern that leads you to call your healthcare provider or even visit the emergency room.”

Vision problems can have many causes beyond multiple sclerosis. But if you have painful vision loss or blurring in one eye that lasts for more than a couple of days, get it checked out.

2. Persistent limb weakness or numbness

You’ve probably had an arm or leg “fall asleep” after sitting in one position for too long, bringing a numbness or tingling feeling that goes away after a few minutes. This early MS symptom feels similar, but it persists for hours or days.

“Everyone experiences twinges or tingles from time to time that come and go but then get better,” Dr. Bermel notes. “But MS affects the central nervous system in a way that causes persistent symptoms.”

He adds that only a small percentage of people who seek medical treatment for numbness, tingling and musculoskeletal issues actually turn out to have multiple sclerosis.

3. Facial paralysis

MS-related muscle weakness can also affect your face, causing the muscles on one side to droop or become temporarily paralyzed. This is called facial paralysis or facial palsy — and it needs attention.

As early signs of multiple sclerosis go, facial palsy is fairly rare. One study found that of 2,260 people living with MS, 3.27% experienced it. And it can have non-MS causes, too, like Bell’s palsy. But either way, it needs to be checked out by a healthcare provider as soon as you notice it.

4. Severe, ongoing dizziness

Your cerebellum and brainstem work together to coordinate a variety of functions and processes, including equilibrium (balance) and muscle movements. When MS causes damage to your cerebellum or brainstem, you may experience severe bouts of dizziness.

Though dizziness can have many causes, MS-related dizziness is typically more severe and lasts for at least two days. You may feel off-balance and unsteady, like you can barely walk without holding onto something.

“MS dizzy spells can cause you to have trouble walking down a hallway, for example, because your sense of equilibrium is so off,” Dr. Bermel says.

Other potential early signs of MS

Research shows that people seek more medical care than usual in the months leading up to an MS diagnosis. The visits are usually for nonspecific issues related to:

  • Musculoskeletal sensations
  • Psychiatric concerns
  • Bladder issues

But researchers need to learn more before they can conclusively link these symptoms to MS.

“We sometimes learn that people have had subtle neurological concerns in the months or even years leading up to their diagnosis,” Dr. Bermel shares. “They‘re ones that wouldn’t have taken people to the emergency department or even to their own doctor — but with hindsight, we suspect that they may have been early signs of MS.”

Is it MS or something else?

Two major clues can help your healthcare provider determine whether an MS relapse or attack could be a cause of what you’re experiencing:

  1. How quickly they appear.Early symptoms of MS are subacute, which means they don’t come on suddenly (like, say, during a stroke), and they don’t slowly worsen over time. “MS is somewhere in the middle,” Dr. Bermel explains. “The symptoms can worsen over hours or days.”
  2. How long they last.MS-related symptoms typically last more than a couple of days. They don’t come and go.

If you notice worrying symptoms, make an appointment with a healthcare provider right away. And because it can be a tricky diagnosis to make, especially in the early stages, you should ideally see a neurologist who specializes in multiple sclerosis.

“This is a condition that really benefits from early treatment,” Dr. Bermel emphasizes, “so it’s important to try to identify MS as early as possible in the disease process.”