Multiple sclerosis (MS) is an immune-mediated inflammatory condition that shares symptoms with many other conditions. Shared symptoms can mean doctors misdiagnose some people.

MS affects around 1 million people in the United States. However, experts believe that around 1 in 5 people with MS could have an incorrect diagnosis.

A conclusive diagnosis involves ruling out other conditions and checking for signs and symptoms that are specific to MS. Healthcare professionals refer to this process as a “differential diagnosis.”

This article describes what MS is, including its symptoms, causes, and treatment. It also investigates how common it is for doctors to misdiagnose MS, lists some conditions with similar symptoms, and explores protocols doctors use to draw a differential diagnosis.

Doctors discussing conditions that are similar to MS.Share on Pinterest
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MS is an immune-mediated inflammatory condition in which the immune system mistakenly attacks the myelin sheath that protects and insulates the nerves of the brain and spinal cord. This disrupts communication between the brain and other parts of the body.

According to the National Institute of Neurological Disorders and Stroke, the symptoms of MS can differ from person to person. However, they may include the following:

The results of a 2019 study suggest that up to 1 in 5 people with MS may have a misdiagnosis.

The study investigated 241 evaluations from people at two separate clinics in the U.S. It found that up to 19% of people diagnosed with MS did not fulfill the McDonald criteria, which doctors use to diagnose MS.

The researchers concluded that these people likely had conditions with symptoms similar to those of MS. The most common misdiagnoses were:

  • migraine (16%)
  • radiologically isolated syndrome (9%)
  • spondylopathy (7%)
  • neuropathy (7%)

According to another 2019 report investigating MS misdiagnoses, misdiagnosis may happen due to doctors:

  • incorrectly applying the McDonald criteria during diagnosis
  • diagnosing conditions solely on the results of an MRI scan without investigating the presence or lack of other symptoms
  • being reluctant to change a past diagnosis of MS despite evidence suggesting a different condition

Here are some conditions that doctors are more likely to misdiagnose as MS.

1. Migraine

Migraine is a complex neurological condition. It causes moderate to severe throbbing headache episodes, typically on one side of the head. Other symptoms of migraine can include:

  • nausea
  • feeling dizzy and unbalanced
  • increased sensitivity to light and sound
  • visual disturbances, such as blurred vision or flashing lights
  • numbness in the hand that moves up the arm and into the face
  • mental fog

Experts do not know the exact cause of migraine. However, temporary changes to chemicals, nerves, and blood vessels inside the brain likely play a role.

Although there is no cure for migraine, treatments can help to reduce the frequency and severity of headache episodes. Possible treatment options include:

2. Radiologically isolated syndrome (RIS)

RIS is a neurological condition characterized by changes or lesions in the brain or spinal cord.

RIS can often indicate MS because the lesions appear very similar to the lesions MS causes. However, a person will not yet have any other symptoms that characterize MS.

Often, a doctor will discover a person has RIS from looking at imaging of the brain done for other reasons, such as trauma to the head or unexplained dizziness. More than half of people with RIS go on to develop MS within 10 years of their initial diagnostic MRI scan.

There is currently no cure for RIS. The treatment depends on whether the doctor determines the person is at low or high risk of developing MS based on various clinical factors. It also depends on how many lesions a person has.

In some high risk cases, a doctor may prescribe medications for MS before the person actually develops the disease. In other cases, a doctor may choose to observe the person for signs that MS is developing while prescribing medication to treat the person’s present non-MS symptoms.

3. Cervical spondylosis

Cervical spondylosis is a type of osteoarthritis that affects the vertebrae of the neck. Symptoms typically include neck pain or stiffness and lower back pain.

This condition can naturally occur with age, typically affecting people over the age of 50 years old. The symptoms can mimic the symptoms of MS, so a doctor will need to do an evaluation and testing to make the correct diagnosis.

The following medications can help to manage the condition and alleviate symptoms:

There are also exercises a person can do to relieve symptoms.

4. Neuropathy

Neuropathy is the medical term for nerve damage or dysfunction. Causes include:

The symptoms of neuropathy depend on the type a person has. Possible symptoms include:

The treatment for neuropathy depends on the underlying cause and the symptoms a person experiences. Treatment options include:

5. Cerebral small vessel disease (CSVD)

CSVD affects the smaller blood vessels in the brain, causing lesions. It is a cause of vascular dementia and can also lead to stroke.

Although multiple factors can cause CSVD, the most common risk factors include the following:

Symptoms and complications of CSVD include:

The treatment for CSVD focuses on medications that relax the small blood vessels, improve blood flow, and decrease blood pressure.

Certain lifestyle changes can also help to manage CSVD. Examples include eating a balanced, nutritious diet and performing regular physical activity.

6. Fibromyalgia

Fibromyalgia is a chronic condition characterized by pain throughout the body. Though it is not entirely clear what causes fibromyalgia, certain factors such as genetics, stress, and changes in the function of the central nervous system may contribute.

Fibromyalgia and MS share several similar symptoms, including headaches, fatigue, and numbness or tingling of the extremities. Other symptoms of fibromyalgia include:

  • dizziness
  • feeling too hot or too cold
  • anxiety
  • difficulty learning new things or remembering information
  • extreme sensitivity
  • stiffness

Treatment often includes a combination of physical activity and talk therapy, which can help improve quality of life and ease symptoms. Doctors may recommend certain medications, including antidepressants, and alternative treatments, such as acupuncture.

7. Vitamin B12 deficiency

Certain medical conditions or dietary changes can cause a vitamin B12 deficiency. Older adults (ages 65 years and over), vegans and vegetarians, people who have undergone bariatric surgery, and those taking certain medications may also be at an increased risk of deficiency.

Symptoms of vitamin B12 deficiency may include:

Depending on the severity and cause of the deficiency, treatment may include oral supplements or injections.

8. Acute disseminated encephalomyelitis (ADEM)

ADEM is a condition that causes a brief, widespread period of inflammation in the brain and spinal cord. This can damage the myelin (protective layer surrounding the nerves).

This condition often occurs after viral or bacterial infection and is more common in children. Rarely, it can also occur after certain types of vaccinations, including those for mumps, measles, or rubella.

Symptoms of ADEM may include:

  • vision loss in one or both eyes
  • difficulty with movement or coordination
  • weakness, sometimes to the point of paralysis

Treatment typically involves the use of corticosteroids to suppress inflammation. Doctors may recommend additional treatment methods to help manage symptoms.

9. Conversion disorder

Conversion disorder, also known as a functional neurological disorder, occurs when a person experiences physical or sensory problems without a physical explanation. A 2022 meta-analysis found that doctors frequently mistake this condition for MS.

Because symptoms typically appear after a period of emotional or physical distress, some experts believe that a reaction to stress or neurological changes may cause conversion disorder.

Possible symptoms of conversion disorder include:

  • changes in vision, hearing, or smell
  • abnormal movements
  • tremors
  • weakness or paralysis
  • numbness
  • seizures

Treatment may involve cognitive behavioral therapy or physical therapy. Doctors may also prescribe medications to treat underlying conditions such as depression or anxiety.

10. Sarcoidosis

Sarcoidosis is an autoimmune condition that causes small areas of inflammation, known as granulomas, to form in body organs.

While it is unclear exactly why some people develop sarcoidosis, some experts believe environmental factors may trigger the condition in people who are more susceptible due to their genes.

Symptoms of sarcoidosis depend on the affected organs. They may include:

Most cases of sarcoidosis do not require treatment, as the condition typically resolves on its own over time. However, in some cases, a doctor may recommend lifestyle changes to manage flare-ups, and certain medications, including steroids.

11. Copper deficiency

Copper is an important mineral involved in energy production, iron metabolism, and brain development. Though it is found naturally in various food sources, some groups may have an increased risk of deficiency, including people with celiac disease or Menkes disease.

Symptoms of copper deficiency include:

Generally, treatment involves addressing any underlying conditions that affect copper absorption. A person may also need to make changes to their diet to help prevent deficiency.

12. Lupus

Lupus is a chronic condition that occurs when the immune system attacks its own tissues, causing inflammation, joint and muscle pain, skin rash, and fatigue.

It is unclear what causes lupus. However, the following factors may contribute to or cause flare-ups of the condition:

  • certain types of medications
  • viral infection
  • sun exposure
  • hormones such as estrogen

Doctors typically treat lupus with medications, including anti-inflammatory drugs and steroid tablets. Diet and lifestyle changes can also help manage symptoms and slow the progression of lupus.

13. Neuromyelitis optica spectrum disorder (NMOSD)

NMOSD, also known as Devic disease, is a condition that causes inflammation of the optic nerve and spinal cord.

Experts believe people with a family history of autoimmune disorders may have a greater risk of developing NMOSD.

Symptoms of NMOSD include:

Doctors may prescribe several medications to treat NMOSD, including immunosuppressant drugs and corticosteroids. They may also prescribe anticonvulsants and antispastics to manage symptoms and help prevent long-term complications.

14. Lyme disease

Lyme disease is a bacterial infection transmitted to humans by a bite from a black-legged tick or deer tick carrying the disease.

One of the first symptoms is typically a rash. It occurs in around 70–80% of people with Lyme disease. It can appear on any part of the body, often has a bull’s-eye appearance, and expands gradually over several days.

Other symptoms of Lyme disease include:

  • fever
  • chills
  • headache
  • fatigue
  • muscle and joint aches
  • nerve pain
  • numbness or tingling in the hands or feet

A doctor will likely treat Lyme disease with an antibiotic. Early treatment is important to help prevent complications and persistent symptoms.

15. Vasculitis

Vasculitis is an autoimmune condition characterized by inflammation of the blood vessels. There are many types of vasculitis, defined by the specific blood vessels affected.

Symptoms of vasculitis can vary depending on the specific type. However, they generally include swelling, fever, and malaise.

A doctor may prescribe medications such as steroids to reduce inflammation and help prevent complications.

According to the National Multiple Sclerosis Society (NMSS), many other diseases and conditions can cause symptoms similar to those of MS. Examples include:

According to the NMSS, a doctor will confirm MS by ruling out other diseases and disorders that may have similar symptoms, as well as checking for signs and symptoms specific to MS. A doctor will also:

  • ask about a person’s medical history
  • ask about family history
  • perform a neurological exam

A doctor may then request the following tests:

  • blood tests to check for certain diseases or deficiencies
  • a lumbar puncture to analyze spinal fluid for antibody abnormalities associated with MS
  • an MRI scan to look for lesions on the brain and spinal cord
  • evoked potential tests, which measure how quickly information passes through nerve pathways

Despite advances in MS research, there is no single test for the condition. As such, diagnosis is not always a straightforward process.

Below are a few common questions about the diagnosis of MS.

What can doctors mistake for MS?

Many conditions share similar symptoms with MS, which can increase the risk of misdiagnosis. According to one 2019 study, some of the most common misdiagnoses include migraine, RIS, spondylopathy, and neuropathy.

How common is MS misdiagnosis?

Doctors can misdiagnose MS. In fact, one study estimates that up to one-fifth of people with MS may be living with a misdiagnosis.

Can doctors misdiagnose MS on MRI?

Misinterpretation of MRI results can be a common cause of misdiagnosis of MS. One study found that only 11% of people referred to an MS subspecialty center based on an MRI result were later diagnosed with MS.

MS affects around 1 million people in the U.S. However, research suggests that up to one-fifth of these people may be living with a misdiagnosis.

Some conditions that doctors may commonly misdiagnose as MS include migraine, RIS, spondylopathy, and neuropathy.

To accurately diagnose MS, doctors must rule out conditions with similar symptoms and look for signs and symptoms specific to MS. As such, the process of diagnosing MS may be lengthy and complex. Nonetheless, an accurate diagnosis is essential to determine the most appropriate course of treatment.