Symptoms of multiple sclerosis (MS) are caused by lesions within the central nervous system. The location of the lesions determines the specific symptoms that an individual may experience. Nausea is one of a wide variety of potential symptoms, but it’s not among the most common.

Nausea can be a direct symptom of MS or an offshoot of another symptom. Also, some of the medications used to treat specific symptoms can cause nausea.

MS pretenders

No single test that can definitively diagnose MS. Part of the criteria for diagnosis is the elimination of other conditions. If you have symptoms of MS, but haven’t been diagnosed yet, your doctor will probably investigate other possibilities to see if they can be ruled out.

Some conditions share many of the same symptoms as MS, but are more likely to involve nausea. These include:

  • stroke
  • migraine
  • brain tumor
  • head injury

Dizziness, vertigo, and movement

Dizziness and lightheadedness are common symptoms of MS that are usually fleeting, but may cause mild nausea.

Vertigo isn’t the same thing as dizziness. It’s the false feeling that your surroundings are moving rapidly or spinning like an amusement park ride. Despite knowing that the room really isn’t spinning, vertigo can be quite unsettling and leave you feeling ill.

An episode of vertigo can last a few seconds or several days. It can be constant or it can come and go. A severe case of vertigo can cause double vision, nausea, or vomiting.

When vertigo occurs, find a comfortable place to sit and keep still. Avoid sudden movements and bright lights. Don’t try to read. The nausea will probably subside when the sensation of spinning stops. Over-the-counter anti-motion sickness medication may be able to help.

If vertigo and associated nausea become an ongoing problem, consult your doctor. Some prescription-strength medications may be able to get your vertigo under control. In extreme cases, vertigo can be treated with corticosteroids.

Sometimes, movement in your field of vision—or even the perception of movement—is enough to trigger severe nausea and vomiting in MS patients. Talk to your doctor if you experience prolonged bouts of nausea.

Medication side effects

Some medications used to treat particular MS symptoms may cause nausea.

Dalfampridine is an oral medication used to improve the ability to walk. One of the potential side effects of this potassium channel blocker is nausea.

A muscle relaxant called dantrolene can be used to treat muscle spasms and spasticity due to a variety of conditions, including MS. Nausea and vomiting after taking this oral medication could indicate serious side effects, including liver damage.

One of the most common symptoms of MS is fatigue. A variety of medications are used to help MS patients overcome fatigue, many of which may cause nausea. Among them are:

Report nausea and other side effects from your medications to your doctor. A change in medication may be all you need to get back on track.