Conditions Commonly Mistaken for Multiple Sclerosis

Have you wondered why your vision got so blurry, or why you feel tired all the time? Maybe you’re having trouble remembering things, and your mind isn’t as sharp as it used to be.

These symptoms can be scary, and it can be frustrating when there are no clear answers about what they may be. Your symptoms could be multiple sclerosis (MS), but they could be something else. One study found that nearly 1 in 5 people with other neurological conditions are mistakenly diagnosed with MS. Because there is no single diagnostic test to receive a definitive MS diagnosis and because symptoms often mimic other illnesses, it can take years to get a final diagnosis.

What is multiple sclerosis?

Multiple sclerosis (MS) is a disease that affects the central nervous system, which is made up of the brain and spinal cord. With MS, the body’s immune system attacks the protective layer, called myelin, that forms around nerve fibers. When the myelin sheath is damaged or destroyed, it disrupts the flow of information from the brain to other parts of the body. The scarring left behind from inflammation to the myelin sheath is called sclerosis.

There are four main types of MS – relapsing-remitting (RRMS), secondary-progressive (SPMS), primary progress (PPMS), and clinically isolated syndrome (CIS). Of the 1 million people living with MS in the United States, 85 percent of them are initially diagnosed with RRMS.

What are the symptoms of multiple sclerosis?

There are several symptoms of MS, but no two people will experience exactly the same symptoms. Symptoms may change or fluctuate over time.

Common symptoms of MS include:

  • MS Hug (dysesthesia)
  • Fatigue
  • Numbness or tingling in the face, body, arms, and legs
  • Muscle weakness
  • Dizziness and vertigo
  • Vision problems
  • Emotional and cognitive changes
  • Bladder problems
  • Changes in gait (walking)
  • Pain

There are also uncommon symptoms of MS, including:

  • Hearing changes—Although vision changes are often one of the first signs of MS, hearing can happen too. According to the National MS Society, about 6% of people with MS experience impaired hearing.
  • Trouble swallowing—Multiple sclerosis can weaken the muscles in the mouth and throat that are needed for swallowing. It can also make it difficult to chew, or it may feel like something is stuck in the throat when there isn’t. This symptom usually appears in the later stages of MS.
  • Muscle spasms—Brief muscle spasms, called paroxysms, can occur in the arms, legs, or in the muscles needed to eat and speak. Although they may occur frequently throughout the day, they tend to go away after a few months

How is MS diagnosed?

The journey to a multiple sclerosis diagnosis can be exhausting and challenging. Since several other conditions have symptoms in common with MS and there are no specific tests for MS, it’s often diagnosed by ruling out other conditions. This means it can take several months, or years, to get an MS diagnosis.

The road to an MS diagnosis typically begins with a careful and detailed medical history. This may then be followed by a neurological exam to assess balance, coordination, hearing and speech, motor and sensory skills, and vision.

The diagnosis for multiple sclerosis is typically made using the McDonald criteria, a tool that doctors use to ensure that they are providing an accurate diagnosis of MS as early as possible. Last updated in 2017, the McDonald criteria requires that there be MRI evidence of damage to the central nervous system at different points in time and different parts of the CNS, including the brain.

What conditions are often mistaken for MS?

A study published in the journal Multiple Sclerosis and Related Disorders found that 17% of people were identified as having been misdiagnosed at one hospital, while 19% were identified as having been misdiagnosed at a second hospital. Familiarizing yourself with MS mimics and their similarities to MS can help bring clarity to the diagnosing process and bring you to an answer sooner rather than later. Here are illnesses that mimic MS:

Lyme disease

Lyme disease is an infection caused by bacteria carried by deer ticks. When left untreated, the Borrelia burgdorferi bacteria levels rise in the bloodstream and travel throughout the body affecting multiple organs and organ symptoms. About 15% of Lyme disease cases become stage two and impact the central nervous system (CNS), known as neurological Lyme disease. Symptoms experienced in stage two are similar to those of MS. These include severe fatigue, Bell’s palsy, vision changes, joint and muscle pain, and cognitive dysfunction.

Despite the similarities between symptoms of MS and Lyme disease, the latter can be diagnosed by determining the likelihood that the patient has been exposed to ticks, as well as lab testing like blood work and lumbar punctures (spinal taps), to detect an infection.


A migraine is a common headache disorder where the headache occurs on one side of the head. They are moderate to severe in intensity and can last for hours, or even days. Migraines can get worse with activity and are often described as a throbbing, pulsing, or stabbing feeling. A study published in Multiple Sclerosis and Related Disorders found that of the people who were misdiagnosed with MS, 16 percent of them received a correct diagnosis of migraines.

Migraines commonly occur in MS and can have similar symptoms like changes in vision, fatigue, and numbness, and tingling in the extremities. The same type of test is used to diagnose both migraines and MS, including reviewing medical history and a neurological exam.

Human T-cell lymphotropic virus-1 (HTLV-1)

Human T-cell lymphotropic virus-1 (HTLV-1) is a rare retroviral infection that affects the T-cells in the body, a specific type of white blood cell. While it’s a rare disease, and often has subtle signs and symptoms, it can present itself as MS. HTLV-1 is associated with progressive spinal cord dysfunction and presents with symptoms like partial paralysis of the lower limbs, stiff muscles, and sensory changes, which are similar to primary progressive MS.

HTLV-1 is diagnosed by blood tests or cerebrospinal fluid. Like MS, there is no cure for HTLV-1 but with the right treatment, many people remain asymptomatic throughout their life.


Fibromyalgia is a chronic condition that affects your bones and muscles, causing widespread pain all over the body. Because pain can often come and go, and the cause is unknown, it can be difficult to diagnose. Fibromyalgia and MS both cause many of the same symptoms, including fatigue, cognitive changes, headaches and migraines, and pain.


Systemic lupus erythematosus (SLE or lupus) is a chronic autoimmune disorder that can cause inflammation and pain anywhere in the body. Like MS, there is no single test to diagnose lupus, and is often called “the great imitator”. Some of the most common neurological symptoms of lupus include migraines, changes in cognitive function, as well as numbness and tingling, fatigue, and muscle pain.

Sometimes, patients with lupus develop transverse myelitis or optic neuritis which may indicate another condition called neuromyelitis optica (NMO). Similar to MS, NMO is a condition where the immune system attacks the spinal cord and optic nerves that cause visual impairment in one eye at a time. Unlike MS, blood tests can diagnose NMO and it requires a different treatment than MS.

Myasthenia gravis

Myasthenia gravis (MG) is a chronic autoimmune, neuromuscular condition that causes weakness in skeletal muscles. Usually, it gets worse after periods of activity and improves after periods of rest, but tends to progress over time. The weakness is caused by an inability to transmit nerve impulses to muscles. Symptoms fluctuate throughout the day and are typically worse at night. Muscle fatigue, tingling in the arms and legs, and blurred vision are all common symptoms of MG. Similar to MS, MG is more common in women than in men.

Sjögren’s Syndrome

Sjögren’s syndrome is another chronic autoimmune disease where the body’s immune system attacks moisture-producing glands, like those that produce saliva and tears. As a result, the most common symptoms for Sjögren’s syndrome are dry eyes and mouth, difficulty swallowing and speaking, fatigue, joint pain, and numbness.

Nerve damage is common in both diseases, so it’s important to differentiate where the nerve damage is located to provide an accurate diagnosis. Tests like nerve conduction velocity (NVC) can help identify if the nerve damage is central as seen in MS, or is peripheral like in Sjögren’s.


Sarcoidosis is an inflammatory disease that is characterized by the growth of inflammatory cells, called granulomas. Usually, granulomas affect the lungs and lymph glands, but they can develop anywhere in the body. Symptoms of sarcoidosis vary depending on the organs affected and may develop gradually over time. Common symptoms include fatigue, pain, and swelling in the joint, and vision changes. It typically appears between the ages of 20 and 40, and women are more likely to develop the disease.

Vitamin B12 Deficiency

In multiple sclerosis, the myelin in the brain and spinal cord are attacked by a person’s immune cells. Damage to myelin disrupts the impulses sent from the brain to the rest of the body. Similarly, when there is a deficiency in vitamin B12 the myelin sheath around nerve fibers doesn’t form properly and impairs nerve signaling. This impairment results in symptoms similar to MS, like weakness, cognitive dysfunction, and trouble walking.

Because the science behind the two diseases is different, diagnosing a vitamin B12 deficiency is much more straightforward compared to MS.

Ms affects the CNS, whereas a vitamin B12 deficiency affects nerves in the central and peripheral nervous system. Symptoms in vitamin B12 deficiency start slower with numbness and tingling, and progress to muscle weakness, and affects legs more than arms. It also tends to affect the middle-aged or elderly, compared to MS which typically begins showing symptoms in young adults.

A simple blood test can diagnose a vitamin B12 deficiency and is easily treatable under the care of a medical professional.

Parkinson’s Disease

Parkinson’s disease, like MS, affects the central nervous system. While MS is a chronic autoimmune disease that causes nerve damage to the myelin sheath over time, Parkinson’s causes cell damage in the brain. Parkinson’s typically begins with tremors, usually in one hand, but other symptoms include loss of balance, stiffness, and slow movement. Like MS, there is no single test to determine Parkinson’s and is determined through blood tests, MRIs, and a DaTscan. Parkinson’s is more common in men than women and is usually diagnosed at age 60 or older, but may affect young adults, too.

You are not alone

Getting a diagnosis of multiple sclerosis can be shocking, and living with the condition can be difficult. Although there is no cure for MS, medication and lifestyle changes can help you manage it. If you need someone to talk to about your condition, there are nearly 75,000 members at PatientsLikeMe who are living with MS and can provide you with the support you need to help manage your illness.

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